The Nazi ‘most wanted’ list

Who was Aribert Heim?

Known as "the Butcher of Mauthausen" or "Dr Death", he was the most wanted of all surviving Nazi war criminals. Heim spent only seven weeks at Mauthausen, the Austrian concentration camp, but in that time murdered hundreds of inmates by carrying out operations, often without anaesthetic, to see what level of pain a human could endure before expiring. Survivors claim he injected prisoners in the heart with various liquids, including petrol, water and poisons, and timed their deaths with a stopwatch to find the most efficient method. On one occasion he is said to have removed the skin of a tattooed prisoner to make seat coverings for the camp commandant's flat.

How did he escape prosecution?

The US military authorities held him for two and a half years after the War but, despite his distinctive appearance (6ft 3in, with size 12 feet and a huge scar on his right cheek), wasn't sure who he was. So while other Mauthausen doctors were tried and hanged, Heim was released without trial. Settling in a spa town near Frankfurt, he married, had three children and practised as a gynaecologist. But in the 1950s the Austrian authorities started an investigation, and in 1962 state prosecutors in Germany issued a warrant for his arrest. Tipped off by Nazi sympathisers, Heim simply climbed into his red Mercedes and sped away.

So what makes us think he's now dead?

Last week his 53-year-old son Rüdiger, who resides in Germany, claimed his father died of cancer in 1992, having lived undetected for ten years in a run-down hotel in Cairo, where he'd converted to Islam and adopted the name Tarek Hussein Farid. And Germany’s ZDF TV says it has found his passport in a dust-caked suitcase handed over by the owners of the hotel. But the claim was greeted with suspicion by the Simon Wiesenthal Center, the Nazi-hunting organisation. "There's no body, no corpse, no DNA, no grave," says the centre's leading Nazi hunter, Efraim Zuroff. Moreover, as recently as 2001 Heim's lawyer claimed a capital gains tax rebate for his client on the grounds that Heim was living abroad. The story could also be a way for Rüdiger to gain control of his father's £1m investments, frozen by German authorities in the 1970s.

Who else is still at large?

In 1947, the UN body Crowcass (Central Registry of War Criminals and Security Suspects) drew up a list of all those wanted for war crimes committed between September 1939 and May 1945: more than 60,000 names. And since the 1950s, some 6,500 have been caught. They include chief architect of the Holocaust, Adolf Eichmann (kidnapped in Argentina by Israeli secret agents, convicted of war crimes in Israel and executed in 1962); Klaus Barbie, the "Butcher of Lyon" (tracked down in South America and tried in France