Stephen Hubbard, 72, was detained in eastern Ukraine in April 2022 and accused of fighting for Ukraine.

A Russian court has jailed a United States citizen for six years and 10 months after convicting him in a closed-door trial of fighting for Ukraine as a mercenary.

Investigators said Stephen Hubbard, who is originally from the US state of Michigan, was paid $1,000 a month to serve in a Ukrainian territorial defence unit in the eastern city of Izyum, where he had been living since 2014.

They alleged the 72-year-old signed up in February 2022, just before Russia launched its full-scale invasion, and was provided with training, weapons and ammunition.

Hubbard was detained by Russian soldiers two months later.

Hubbard’s case first became public late last month when his trial began and he entered a guilty plea. At a hearing last week, the court granted the prosecutors’ request for the proceedings to be held in secret without the media.

Hubbard, who was handcuffed, shuffled slowly into the Moscow City Court and stood with difficulty as Judge Alexandra Kovalevskaya read out the sentence, according to journalists from the Reuters and AFP news agencies who were in the court.

Russia’s state news agency RIA reported that Hubbard’s lawyer planned to lodge an appeal.

US State Department spokesperson Matthew Miller said that Washington had limited information about the case because Russia had refused to grant consular access to Hubbard.

He confirmed that Hubbard had been arrested two years ago in Ukraine.

“We’re disappointed, as we often are, when they refuse to grant consular access,” Miller told reporters in Washington. “They have an obligation to provide it and we’re going to continue to press for it. We’re looking at the case very closely and considering our next steps.”

Hubbard’s sister Patricia Hubbard Fox and another relative have cast doubt on his reported confession, telling Reuters he held pro-Russian views and was unlikely to have taken up arms given his age.

In interviews, Fox and the other relative portrayed Hubbard as an isolated figure who had grown estranged from some family members during decades abroad teaching English, including in Japan and Cyprus.

Fox said Hubbard moved to Ukraine in 2014 and lived there for a time with a Ukrainian woman, surviving off a small pension of about $300 a month. He never learned Russian or Ukrainian, she said.

Hubbard is one of at least 10 Americans behind bars in Russia, nearly two months after a prisoner swap between Moscow and the West freed three Americans, including Wall Street Journal reporter Evan Gershkovich, and dozens of others.