Polish authorities have accused a US citizen of being a former Nazi commander and want him extradited back to Poland.
Michael Karkoc, 98, is accused of being a commander of a Nazi SS-led Ukrainian unit, and in 2013 he was accused of ordering the massacre of at least 44 Polish civilians during World War Two.
However Karkoc's son, Andriy Karkoc says his dad is innocent.
"My father was, is, and remains an innocent man," he said.
"These are lies, this is defamation, this is slander, it's unsupported, it's innuendo, it's allegations."
Despite those claims, Polish authorities say they have plenty of evidence pointing to Mr Karkoc holding that role in the Third Reich.
They say they have records of Nazi payments, testimonies from other soldiers and Mr Karkoc's own diary written in Ukrainian, in which he writes about him being at the site of some of the deaths.
Karkoc also failed to declare his past history to United States officials when he applied for citizenship in 1949, which authorities say would have stopped his application.
German authorities investigated Mr Karkoc four years ago but decided not to prosecute after finding him mentally incompetent to stand trial.
The US Justice Department has yet to comment on whether they will extradite the suspected former Nazi commander to stand trial in the country where he allegedly once shot its citizens.