WARSAW, Poland - Poland's special prosecutors say they have taken steps toward seeking the extradition from the U.S. of a Minnesota man they accuse of participating in a World War II massacre.

The Associated Press had previously identified the man as 98-year-old Michael Karkoc, an ex-commander in an SS-led Nazi unit that burned Polish villages and killed civilians -including women and children- during the war.

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The National Remembrance Institute said Tuesday the request was forwarded to Poland's Embassy in Washington last month for handing over to U.S. justice authorities.

The motion's status could not be immediately confirmed as the embassy was closed for the July 4 U.S. holiday.

"It’s a manufactured hoax masquerading as a slander and a libel against my family, against my father, against Ukraine and Ukrainians generally," Andriy Karkoc, who is the son of Michael Karkoc and a family spokesperson, told KARE Tuesday.

"In 1972, 45 years ago, the Polish government tried and convicted another man of the crimes that they’re now trying to extradite my father for now. I cannot understand under what circumstances that can be legitimate or even legal for that matter."

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

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<p>Prosecutors say evidence they've gathered proves "100 percent" that MN resident Michael Karkoc was a World War II commander of a unit in the SS-led Ukrainian Self Defense Legion, accused of burning villages and killing civilians in Poland.</p>