WARSAW, Poland — Poland will seek the arrest and extradition of a Minnesota man exposed by The Associated Press as a former commander in an SS-led unit that burned Polish villages and killed civilians in World War II, prosecutors said Monday.

Prosecutor Robert Janicki said evidence gathered over years of investigation into U.S. citizen Michael K. confirmed “100 percent” that he was a commander of a unit in the SS-led Ukrainian Self Defense Legion.

He did not release the last name in line with privacy laws but the AP has identified the man as 98-year-old Michael Karkoc, from Minneapolis.

“All the pieces of evidence interwoven together allow us to say the person who lives in the U.S. is Michael K., who commanded the Ukrainian Self Defense Legion which carried out the pacification of Polish villages in the Lublin region,” Janicki said.

The decision in Poland comes four years after the AP published a story establishing that Michael Karkoc commanded the unit, based on wartime documents, testimony from other members of the unit and Karkoc’s own Ukrainian-language memoir.

Karkoc’s family has repeatedly denied he was involved in any war crimes and his son questioned the validity of the evidence against him after Poland’s announcement, calling the accusations “scandalous and baseless slanders.”

“There’s nothing in the historical record that indicates my father had any role whatsoever in any type of war crime activity,” Andriy Karkoc said.

He questioned the Polish investigation, saying “my father’s identity has never been in question nor has it ever been hidden.”

If convicted of contributing to the killing of civilians in 1944, Karkoc could face life in prison.