Prosecutor Robert Janicki said evidence gathered over years of investigation into US citizen Michael K confirmed "100 per cent" 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 US is Michael K, who commanded the Ukrainian Self Defense Legion which carried out the pacification of Polish villages in the Lublin region," Janicki said.
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".
Also Read
"There's nothing in the historical record that indicates my father had any role whatsoever in any type of war crime activity," said Andriy Karkoc.
He questioned the Polish investigation, saying "my father's identity has never been in question nor has it ever been hidden".
"The prosecutor in Lublin intends to direct a motion to the US justice authorities asking that the suspect...Be handed over to Poland," the institute said in a statement.
Janicki added 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 1944, Karkoc could face life in prison.
Disclaimer: No Business Standard Journalist was involved in creation of this content