John Demjanjuk, 88, will face trial in Germany with prosecutors now seeking his extradition from the U.S.

'In this capacity, he participated in the accessory to murder of at least 29,000 people of the Jewish faith,' Munich prosecutors said in a statement today.

Kurt Schrimm, Germany's chief war crimes investigator, said new files and witnesses provided 'a great chance' to make Demjanjuk  'face up to the  responsibility for his crimes'.

Dr Schrimm says he can prove that the man born Ivan Demjanujuk served in Sobibor extermination camp, which was in Nazi-occupied Poland, for six months in 1943.

To give a sense of the scale of the killings carried out there between March 1942 and October 1943 an estimated 250,000 people were murdered.

'We have managed to obtain hundreds of documents and have found a number of witnesses who spoke out against Demjanjuk,' said Dr Schrimm.

'For the first time we have even found lists of names of the people who he personally led into the gas chambers. We have no doubt that he is responsible for the death of over 29,000 Jews.'

He said a trial would take place in Munich, Germany, because 1,900 victims were thought to be German Jews.

In 1988, Ukranian-born Demjanjuk was found guilty in Israel of being 'Ivan the Terrible', a guard who herded women and children into the gas chambers of the  Treblinka extermination camp in Poland.

However, five years later he walked free from an appeal court after his conviction was overturned.

Prosecutors accepted that recently released KGB archives cast reasonable doubt that Ivan was in fact someone else.

But that case of mistaken identity led Nazi hunters to examine his background more closely. Now they are certain that he was in fact a guard at the equally infamous the extermination camp of Sobibor.

Experts from the Bavarian State Office of Criminal Investigation recently verified the validity of Demjanjuk's ID, which puts him in the camp during the period when the crimes took place.

American and German prosecutors say they have seven 'water-tight' pieces of  evidence placing Demjanjuk in Sobibor including an authentic SS identity  card, pay book, ration cards and SS documents detailing times, places and victims.

It was 1977 when the past of the retired Ford worker from Cleveland, Ohio, first came under scrutiny.

He was subsequently stripped of his U.S. citizenship and extradited to Israel where he faced the charges of being 'Ivan the Terrible'.

On his release in 1993 he was allowed to return to the U.S. But since then more and more evidence has emerged placing him in Sobibor.

Demjanjuk  denies any involvement in war crimes and has maintained that the Nazis captured him as a prisoner of war while he was serving in the Soviet Army  and forced him into the SS but that he never killed anyone.

In May last year the U.S. Supreme Court refused to hear his final appeal which clears the way for Demjanjuk to be extradited to Germany to face the new charges.

The extradition paperwork is now finished and will be lodged with American officials by the end of this month.