Washington, Sep 6 (DPA) An 87-year-old Ukrainian immigrant has lost his appeal to keep his US citizenship after a US federal court has ruled that he had collaborated with Nazis during Germany's occupation of Ukraine and helped liquidate a Jewish ghetto in Poland.

Ruling in the four-year-old case, the Sixth Circuit Court of Appeals said that John Ivan Kalymon had lied about his involvement with the Ukrainian Auxiliary Police (UAP) when he emigrated to the US from Germany in 1949, US justice officials said Friday.

The Troy, Michigan, resident became a US citizen in 1955.

US investigators charged that as a member of the UAP, Kalymon had helped round up Jews, imprison them in a ghetto, terrorize them and supervise their forced labour, kill those trying to escape and lead survivors to extermination and forced labour camps, including Belzec in Poland.

He allegedly committed the crimes in Lviv, formerly in Poland and now part of Ukraine, from 1941-1944.

The court decision from Thursday was announced Friday by acting assistant attorney general Matthew Friedrich of the US justice department's criminal division.

The court based its decision in part on UAP documents, including one signed by Kalymon that 'proved that in 1942 he personally killed and wounded Jews in Lviv by shooting them,' a statement from the justice department said.

'The Nazis and their collaborators killed more than 100,000 of Lviv's Jews - men, women and children whose only 'crime' was their religion,' said Eli Rosenbaum, director of the Office of Special Investigations that continues to probe Nazi-era crimes.

He called the decision by the court, which serves Michigan, Tennessee, Ohio and Kentucky, an 'important victory in the US government's ongoing effort to secure a measure of justice on behalf of the victims of Nazi inhumanity'.

Many of the UAP's and Kalymon's victims were sent to the Belzec, Poland, extermination centre where they were murdered with poison gas, prosecutors said.

The court ruled that Kalymon had not been eligible for US citizenship because of his collaboration with the Nazis, and because he hid this information when he applied for a US visa. It was not clear if he would be allowed to stay in the US.

OSI said it has won cases against 107 individuals who assisted in Nazi persecution during World War II. Another 180 have been blocked from entering the US because of the OSI's watch-list.

One of the most famous Ukrainian cases involved John Demjanjuk, 88, the Ukrainian-born man alleged to have been a brutal guard at the Nazi's Treblinka death camp.

In a case dating back 30 years, Demjanjuk has been extradited to Israel, acquitted by an Israeli court, returned to the US and had his US citizenship revoked. Until recently, no country had offered to take him.

In June, Germany's top Holocaust crimes prosecutor Kurt Schrimm said he would apply to the German high court for Demjanjuk's extradition to be prosecuted under German criminal law.

The court would first have to decide if German prosecutors had authority over the case.