Matt Elton: Before we talk about the part you played in the hunt for Josef Mengele, can we briefly set out his role in the Holocaust?

Gerald Posner: Mengele was a doctor at Auschwitz, where he did two things for which he’s become notorious. First, he conducted all kinds of human experiments, some on children and many on twins.


And, second, he waited at the camp entrance for trains to arrive packed with people, mostly Jews, from all over Nazi-occupied Europe, and selected who lived and who died.

He wasn’t the only Nazi doctor at Auschwitz, but he became the most notorious for his enthusiasm for his gruesome work – and for escaping after the war and remaining a fugitive for many decades.

Mengele (centre) pictured with two commandants of Auschwitz, Richard Baer (left) and Rudolf Höss, at an SS retreat in 1944. (Photo from AKG Images)
Mengele (centre) pictured with two commandants of Auschwitz, Richard Baer (left) and Rudolf Höss, at an SS retreat in 1944. (Photo from AKG Images)

Did his crimes mean he was regarded as particularly worthy of being brought to justice after the war ended?

There was a limit to how many Nazis could be brought to justice. Some 50,000 worked at the camps in different positions, from guards to doctors and overseers to commandants. About 2,500 were eventually tried; thousands more returned to normal lives after the war without paying any price for their actions.

It may be hard to accept, but not every Nazi at every concentration camp liked the work. Some were sadistic, and some were pathological, but for many it was not considered a great assignment.

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Auschwitz was in Poland, where summers were hot and winters freezing – bad for the prisoners, but also for those who worked at the camps. I don’t mean to suggest that anyone should feel sorry for the Nazis, but some of them didn’t like it.

That’s not the case with Mengele. He relished it: he viewed Auschwitz as a step up in his career, as a way to make a name for himself.

What did Nazis do when it became clear that the war was coming to an end?

The regime started to collapse very quickly at the end of 1944, and hardline Nazi zealots had two main goals. The first was to cover up their crimes, so at camps including Auschwitz they destroyed the gas chambers and tried to destroy the crematoriums.

Then they tried to escape west. They didn’t want to stay in Poland, because Soviet troops – who had a reputation for brutality – were coming, and seeking vengeance for the terrible sufferings inflicted on them during the Nazi invasion of the Soviet Union.

So Nazi officials wanted to escape – but if they couldn’t, would rather be caught by the Americans or the British.

Mengele was caught twice by the Americans and released, along with many others, among the millions of displaced people after the war.

Mengele spent four years in Europe – in Czechoslovakia and Germany – after the war. How was he able to stay for so long?

Actually, it wasn’t so unusual. For example, the chief pharmacist at Auschwitz, Victor Capesius, who had stolen gold from the teeth of corpses, went to West Germany after the war and opened a pharmacy.

Mengele knew that he was being searched for, but expected that the British and the Americans would eventually leave their occupied zones and return control of the country to the West Germans, who would say: “We’re so sorry for the terrible things that happened, but now let’s get on with fighting the Cold War.”

Then, in 1948, a number of people with whom Mengele had served at Auschwitz were tried. They were being sentenced to death or to long prison sentences. So at that point, Mengele opted to go to South America.

Because it was far away! But the reason that Argentina was the nation to which most of the Nazis went was because, although it was neutral in the war, it had a large German community who thought that the Germans had been punished too much after the conflict ended.

The Allies put Nazis on trial for war crimes – but if it had been the other way around, and Germany had won, they thought that there may instead have been trials of the British pilots who had firebombed Dresden and the American pilots who had dropped the atomic bombs on Hiroshima and Nagasaki. That’s not a moral equivalency, but it’s how they justified it to themselves.

So when Mengele and other Nazis arrived in Argentina, they found a country in which there was already a network of Nazi sympathisers and a large German community to welcome them.

How was it possible for Mengele to stay undetected in South America for decades?

He arrived with some money from the Mengele family farm-machinery manufacturing company, and gradually started to feel as though the Nazi hunters weren’t interested in him.

At one point in the mid-1950s, he walked into the West German embassy in Buenos Aires and said: “By the way, my name is not really Helmut Gregor [the fake name in the fake passport on which he’d arrived in 1949], it’s Josef Mengele, and I would like a passport in my real name.”

A photo of Mengele's papers, with the name Helmut Gregor
The papers with which Mengele gained entry to Argentina in 1949, using the name Helmut Gregor. There he joined a network of fugitive Nazis. (Photo from AKG Images)

Nobody in the West German embassy said: “You’re the right age to have served in the Second World War, you arrived in Argentina under a fake name, and now you’re giving this name? I’ll check to see if it’s on the wanted list.”

It was a remarkable bit of incompetence and apathy that allowed him to live there in style and comfort. I also think that the West German embassy had been penetrated by Argentine Nazi sympathisers.

It’s almost impossible now to establish who put his application through. But it is astonishing that this Nazi fugitive felt so comfortable that in 1958 he was listed in the Buenos Aires phonebook under his real name. All you needed to know was which city to look in and you would have found him.

In 1960, near Buenos Aires, the Israelis kidnapped Adolf Eichmann, the bureaucrat who ran the trains to the concentration camp. That’s when Mengele decided to move away from Argentina.

A black and white photo of Adolf Eichmann standing trial, with two men in uniform standing behind him.
Adolf Eichmann stands trial in Jerusalem, 1961, following his capture in Argentina. Mengele fled the country to avoid a similar fate. (Photo by Popperfoto via Getty Images)

How and why did you first become involved in this story?

In 1981, I had just joined a small law practice in New York City when a friend told me that the US Department of Justice (DoJ), where he worked, had been approached by Auschwitz survivors – twins who’d been experimented on as children by Josef Mengele.

They asked whether the DoJ might bring an action against the German government to try to find Mengele. It couldn’t, but my friend asked if I might help these twins.

So I met Marc Berkowitz and his sister Francesca. Marc wanted money from the German government to pay for his medical bills – the thousands of dollars that he’d spent over many years trying to heal the pain caused by what Mengele had done to them in the camp.

In fact, we found that of the 1,500 sets of twins on whom Mengele had experimented, about 140 were still alive in 1981.

I tried to sue the Mengele family, but we were thrown out of the Federal Court because I couldn’t produce evidence that they had been supporting him as a fugitive. Yet it sparked a passion in me, and I kept pursuing what I thought was the case against Mengele, and trying to determine where he was.

Where did you think he was at that time?

I was convinced that Mengele was living the high life in Paraguay, under the then-dictator Alfredo Stroessner. We knew that he had acquired Paraguayan citizenship in 1959, when he first fled from Argentina, under the name José Mengele – not a very good alias, but good enough to throw those hunting him off the scent.

We suspected that he was hiding out in the Chaco region of Paraguay, or perhaps in the heavily German area around Hohenau in the south-east.

A whole range of sightings, books and movies about Mengele – Marathon Man, The Boys from Brazil – had propagated the myth that he was hiding in the jungle, surrounded by killer dogs and armed guards, riding around in a Mercedes limousine and being funded by his family.

That image is one of the reasons he got away – because, instead, he was actually living a very low life in the poorest barrios outside São Paulo, Brazil. He wasn’t the superhuman Nazi fugitive living the Hollywood version – he was the Nazi doing anything to survive, and that kept him free.

Books and movies propagated the myth that Mengele was hiding in the jungle, with killer dogs and armed guards

Amid all this hype and mythologisation, how did you go about finding the truth?

It was known that Mengele had been in Argentina, but nobody knew the details. The Argentine government, which was run for nearly 15 years by a military junta across two periods from 1966 to 1973 and 1976 to 1983, had been asked repeatedly for its Mengele file by the US DoJ, by the Israelis, the British, the West German government – and always ignored that request.

Good research sometimes involves lucky timing. I first visited Buenos Aires in November 1984, not long after the Falklands War. The military junta had been overthrown, and a new civilian government was in power.

I went to the Presidential Palace and made a request in writing for the Mengele file, and talked to a human-rights advisor to the newly elected president. I also sat in a downtown hotel for about three weeks doing interviews.

Then, at about 11pm one night, there was a knock on the hotel-room door. Two members of the Argentine federal police were outside, who told me to come with them. They took me to a blue Ford Falcon – which, as I quickly learned, was not a good sign, because under the military junta blue Falcons had been used for taking away political prisoners.

They took me to their headquarters and to a very grumpy colonel. I didn’t know what was happening until I realised he had been ordered by the civilian government to open their Mengele file.

On a desk in a side room was a folder detailing 10 years of Mengele’s life on the run: his entry into the country, his false passport, his application to the West German embassy, his businesses, his marriage.

A photo of Josef Mengele in his later years. (Photo by GTV/Shutterstock)
A photo of Josef Mengele in his later years. (Photo by GTV/Shutterstock)

It was only later that I realised how lucky I had been. Six weeks after I had gained access to that file, a British journalist applied to see the same material and was rejected. The government had realised that it didn’t have to say yes to every request and closed the door.

So I’d love to say that I deliberately took advantage of that , but I was mainly just fortunate. And that opportunity then led me to Paraguay and beyond – except for the last, most vital part of the story, when Mengele was in Brazil, because the documents only went up to 1959.

You mentioned that you carried out interviews. Who did you speak to?

In Buenos Aires I interviewed Wilfred Von Oven, an assistant to Joseph Goebbels. I was convinced that he knew Mengele’s location, and spent a lot of time trying to get information from him, but got nowhere.

Instead he would show me pictures from Miss Nazi contests – and yes, things like that existed at the time down in this little Fourth Reich.

There was a kind of industry in South America in tales about Nazis. So if you were a journalist or lawyer looking for Mengele, people came out of the woodwork to say: “Oh, I used to go bowling with him,” or “He taught my child how to speak German.”

So you had to weave through a minefield. These people weren’t asking for money, they just wanted a bit of fame. So two-thirds of the information I pursued in Argentina and Paraguay would have made a great novel, but wasn’t useful for finding out what had happened to Mengele.

When did you realise that he was dead?

Not until 1985. The previous year, I had signed a book deal to co-write a biography of Mengele with a British journalist, John Ware.

We were halfway through that manuscript – and still believed Mengele was alive – when at about 4.30am one morning, I got a call from a German reporter telling me that bones had been found in Embu, near São Paulo, that were thought to belong to Josef Mengele.

A grey-haired male doctor in a white labcoat holding a human skull and pointing to the middle of it, showing it to a group of students in white labcoats.
Forensic doctor Daniel Muñoz, who led the team that identified Mengele’s body in 1985, with
his remains at Sao Paulo University’s school of medicine. They are now used as teaching aids. (Photo by AP Photo/Andre Penner, via Alamy)

I initially thought it was junk – it must have been something like the 12th time that they had apparently found his remains – so my initial reaction wasn’t that this was fantastic news. But a day later, I set off for Embu – and while I was there my view started to change.

It was down to another bit of serendipity. News articles had been published revealing that I had the largest private archive on Mengele.

And while I was in Embu discussing with the forensic pathologists the authenticity of the bones – which turned out to be real – Mengele’s only son, Rolf, showed up at the German publisher of celebrity magazine Bunte, offering them what he claimed were thousands of pages of his father’s personal diaries from his years on the run, along with correspondence sent to Rolf.

A black and white photo of the front cover of Bunte, with Josef Mengele on the front cover.
A picture that Rolf took of his father in 1977 on the front cover of Bunte in 1985. (AP Photo/Helmuth Lohmann, via Alamy)

Bunte was tempted but cautious – this was just two years after the publication of the fake ‘Hitler Diaries’ that had been serialised in the German magazine Stern and in The Sunday Times, and which had fooled British historian Hugh Trevor-Roper.

So the publisher decided to have the documents assessed by the German version of the FBI. They also brought in a panel of experts and asked me – because of my huge archive – to be the only non-historian in the group.

A photo of Gerald Posner (left) and Rolf Mengele (right) seated together at a dark table, both wearing suits. Gerald is holding a white A4 sheet of paper, and Rolf has his hands loosely clasped together on top of the table.
Documents held by Mengele’s son Rolf – seated (right) with Gerald Posner in Germany, 1986 – were key to unlocking the mystery of his final years. (Photo by Gerald Posner)

So in Munich, every day for two weeks, we grilled Rolf Mengele about how he’d obtained the documents, when he’d last seen his father, all the details. It turned out that those documents were real – and I was able to use them in my book.

How did Mengele’s survivors react to the news that he was dead?

Many survivors refused to believe it, and I understand that. One said to me, and I’m paraphrasing: “We saw him at his most evil; a God-like figure who controlled life and death. So if there’s a one in a million chance that the remains in Brazil are not his, I’ll believe it’s not him. He’s capable of anything.”

I was among the people disappointed that the story ended with him getting away. It’s often said that putting him on trial wouldn’t have led to justice, and that’s true – but as Eichmann’s trial showed, it would have added so much detail to the historical record.

What was particularly infuriating about Mengele was that he was unrepentant. Until his dying day, he never was sorry for what he had done at Auschwitz.

Two years before he died, Rolf visited him in South America to confront him about Auschwitz, and he responded, essentially: “You’ll never under- stand what we were trying to accomplish.”

What did Auschwitz survivors want to see happen to Mengele?

People often assume the survivors I spoke to wanted vengeance – to see Mengele pay for his crimes. But what they really wanted was to know what he did to them at the camp: what was injected into them, what experiments he undertook.

Two women looking at photographs on a wall that are part of an exhibition.
Two of Mengele’s victims, twins Lia Huber and Judith Barnea, at the Yad Vashem memorial in Jerusalem, 2018. As Mengele never left behind medical records, what he sought to achieve from his brutal experiments remains a mystery. (Photo by GALI TIBBON/AFP via Getty Images)

They knew that he had injected their eyes; that he had done spinal taps without pain relief; that, in some cases, he had even performed amputations. But they didn’t know what it was for.

Was it for sterilisation? To unlock the mystery of twin births so that German mothers could have more children after the war? Was it to turn dark eyes blue? Mengele didn’t leave behind his medical records, so the reasons for those experiments were locked up in his own head.

People assume that the survivors wanted vengeance, but what they wanted was to know what Mengele did to them at the camp

The only way survivors might find out what had been done, and how to treat themselves as result, was to find out what he had injected into them and why. That was the mystery he held for them – something I had never expected until I started to talk to them.

Decades on, how do you now see this story and your role within it?

For me, the fact that Mengele died of natural causes, swimming off a beach near São Paulo in 1979, is an indictment of the people who should have been looking for him and failed to find him.

After the Israelis caught Eichmann in 1960, they closed the book on Nazis, but the West Germans could have broken this case with a simple mail intercept. Mengele sent letters back to his family, and they were kept by a senior executive in the Mengele firm, who the West Germans knew was a childhood friend.

And if they had put a travel notice on Rolf, they would have realised he was travelling under a false document when he went to South America in 1977, and could have easily caught up with Josef.

This was not a difficult case to break – but nobody in the West German prosecutors’ offices had the passion or the wherewithal to chase down this ageing Nazi decades after the war and put him on trial for his crimes. The fact that he got away with it isn’t because he was so clever, but because those looking for him just didn’t have enough desire to undertake the investigation.

Another reason I’d have relished the idea of him on trial is because, in the face of all the Holocaust deniers we’ve seen emerge in the decades since, Mengele would have spoken in a clear voice about what he did without any apologies.

He would have tried to defend his work as a zealous doctor doing experiments in Nazi ideology and racial theory. That, I think, would have been hugely important.

Gerald Posner is an investigative journalist and writer. He co-authored (with John Ware) Mengele: The Complete Story (McGraw-Hill, 1986)


This article was first published in the October 2023 issue of BBC History Magazine


Matt EltonDeputy Editor, BBC History Magazine

Matt Elton is BBC History Magazine’s Deputy Editor. He has worked at the magazine since 2012 and has more than a decade’s experience working across a range of history brands.