Poland is to seek the extradition of a Minnesota man suspected of being a Nazi unit commander who ordered the killing of 44 Poles during World War Two.
Prosecutor Robert Janicki said various evidence gathered in years of investigation into US citizen Michael K confirmed "100%" that he was a commander of a unit in the SS-led Ukrainian Self Defence Legion, which is accused of burning villages and killing civilians in Poland.
The man's last name was not released in line with the country's privacy laws, but he has been identified by the Associated Press as 98-year-old Michael Karkoc, from Minneapolis.
His family deny he was involved in any war crimes.
Prosecutors of the state National Remembrance Institute asked a regional court in Lublin, Poland, to issue an arrest warrant for Mr Karkoc.
If granted, Poland would seek his extradition because it does not allow trial in absentia, Mr Janicki said.
He said the man's age would be was no obstacle in seeking to bring him before justice.
"He is our suspect as of today," Mr Janicki said.
If convicted of contributing to the killing of civilians in the villages of Chlaniow and Wladyslawin in July 1944, Mr Karkoc, a retired carpenter, could face a prison term for life.
German prosecutors previously launched their own investigation into Mr Karkoc after claims he had been a former commander in the SS-led unit that had committed war crimes in Poland.
Although there was never any doubt expressed over Mr Karkoc's identity, they shelved their investigation after doctors at the geriatric hospital in the US where he was being treated provided medical evidence that led them to conclude he was not fit for trial .