Former U.S. Marine Robert Gilman, who serves a sentence for attacking a police officer and is accused of assaulting a prison official, reads a document inside an enclosure for defendants as he attends a court hearing in Voronezh, Russia October 7, 2024. REUTERS/Vladimir Lavrov/File Photo

MOSCOW (Reuters) -Russian prosecutors have filed fresh charges against Robert Gilman, a U.S. citizen and ex-Marine serving an eight-year sentence for assaulting law enforcement officers and a prison official, court documents show.

Gilman, 30, was first arrested in 2022 for a purportedly drunken assault on a Russian police officer. His sentence has been extended several times following convictions for assault against prison officials and a state investigator during his incarceration.

Gilman previously told a court he was forced to use violence after the prison inspector had caused pain to his genitalia and after the investigator had insulted his father.

The new charges, filed in late July in a court in Voronezh in southern Russia, also concern assault against prison staff.

Gilman could not be reached for comment and his lawyer did not immediately respond to a request for comment.

The Kommersant newspaper reported that Gilman's defence team had requested he receive a more lenient sentence, citing an unspecified mental health condition.

The next court hearing in his case is scheduled for August 25.

Gilman is one of around nine Americans behind bars in Russia.

The most recent U.S.-Russia prisoner swap, in April, saw Ksenia Karelina, a Russian-American spa worker who lived in Los Angeles, swapped for a Russian whom the U.S. had accused of spiriting sensitive electronics to the Russian military.

(Reporting by Reuters; Writing by Lucy PapachristouEditing by Andrew Osborn)