(AP) Poland will seek the arrest and extradition of a Minnesota man after confirming he was a Nazi unit commander suspected of ordering the killing of 44 Poles during World War II, a prosecutor said Monday.

Robert Janicki said that various evidence gathered in years of investigation into US citizen Michael K. confirmed “100 percent” that he was a commander of a unit in the SS-led Ukrainian Self Defense Legion, which is accused of burning villages and killing civilians in Poland.

The Associated Press has identified the man as 98-year-old Michael Karkoc, from Minneapolis.

Karkoc’s family denies that he was involved in any war crimes.

Prosecutors of the state National Remembrance Institute have asked a regional court in Lublin, Poland, to issue an arrest warrant for Karkoc. If granted, Poland would seek his extradition, as Poland does not allow trial in absentia, Janicki said.

He said the man’s age was no obstacle in seeking to bring him before justice.

“He is our suspect as of today,” Janicki said.

If convicted of contributing to the killing of civilians in the villages of Chlaniow and Wladyslawin in July 1944, Karkoc could face life in prison.

Prosecutors in Germany previously launched their own investigation of Karkoc after stories in 2013 by The Associated Press revealing that he had been a former commander in the SS-led unit that had committed war crimes in Poland.

They never expressed doubts about Karkoc’s identity, but shelved their investigation after saying they had received “comprehensive medical documentation” from doctors at the geriatric hospital in the US where he was being treated that led them to conclude he was not fit for trial.

The Simon Wiesenthal Center’s top Nazi hunter, Efraim Zuroff, is applauding Polish prosecutors for deciding to seek an arrest warrant for this man suspected of war crimes.

Zuroff told The Associated Press by phone from Jerusalem on Monday that “it’s high time that the Poles became more active seeking people who committed crimes in World War II on Polish soil.”

He says that taking such legal steps “sends a very powerful message.”