Stephen James Hubbard, a 72-year-old U.S. citizen, pleaded guilty in a Moscow court on Monday to charges of serving as a mercenary against Russia in the Ukraine war, Russia's RIA news agency reported.
Hubbard's sister and another relative quickly cast doubt on his reported confession, telling Reuters he held pro-Russian views and was unlikely to have taken up arms at his age.
RIA said Hubbard had admitted in a hearing at the Moscow City Court that he had received money to fight for Ukraine against Russia.
"Yes, I agree with the indictment," RIA quoted him as saying.
Hubbard was placed in pre-trial detention last week for six months. He faces a sentence of seven to 15 years if convicted.
RIA, citing a prosecutor in court, said Hubbard had signed a contract with a Ukrainian territorial defense unit in the eastern Ukrainian city of Izyum at the start of the war in February 2022.
The prosecution said he was promised $1,000 a month and was provided with training, weapons and ammunition. RIA quoted the prosecutor as saying Hubbard was detained by Russian soldiers on April 2 of that year, just weeks after the war began.
Reuters was unable to confirm how Hubbard was detained. His lawyer could not immediately be reached. The Ukrainian Foreign Affairs Ministry did not immediately reply to messages seeking comment.
Hubbard's sister, Patricia Fox, last spoke with him in September 2021, via Skype. She questioned his reported confession.
"He is so non-military," she told Reuters by phone. "He never had a gun, owned a gun, done any of that...He's more of a pacifist."
Hubbard is one of at least 10 Americans behind bars in Russia, nearly two months after a prisoner swap on Aug. 1 between Moscow and the West freed three Americans and dozens of others.
A spokesperson for the U.S. embassy in Moscow said last week it was aware of the detention of an American citizen, but declined further comment.
A native of the small town of Big Rapids, Michigan, Hubbard worked for decades as an English teacher abroad, including in Japan and Cyprus, his sister said.
Fox said Hubbard moved to Ukraine in 2014 and lived there for a time with a Ukrainian woman, surviving off a small pension. When she last spoke to him, he had split from his girlfriend and was living alone in Izyum, she said.
Fox said she had received little information about her brother's status for months until a video surfaced online.
The video, posted to YouTube in May 2022 by an account with just over 100 followers, shows a bearded man in a brown sweater sitting facing the camera and answering questions from an off-camera interviewer, who speaks with accented English.
It is unclear where and when it was filmed, but Fox identified the man as her brother.
In the video, the man says he understands why Russian President Vladimir Putin sent troops into Ukraine and expresses hope that the war will end soon.