A Polish prosecutor pursuing a Nazi crimes investigation of a Minnesota man said experts would compare the man's photos with a picture of a Nazi commander to make sure they are the same person.

Michael Karkoc served as a World War II commander of a unit in the SS-led Ukrainian Self Defense Legion, which is accused of burning villages in Poland, Kresy.pl reported, adding that he emigrated to the U.S. in 1949 and eventually got work as a carpenter.

Karkoc, 97, published a memoir in 1995 confirming he was an SS officer but did not address the massacres. If Polish investigators confirm his identity, the country would seek to extradite him, Kresy.pl added.

Prosecutor Dariusz Antoniak said Thursday experts were working to confirm whether Karkoc was the same person as the Nazi commander by comparing photos of Karkoc with a 1940 photo of the commander, taken in Ukraine.

Kresy.pl and The Associated Press contributed to this report.