A Moscow court has sentenced a Russian-born US citizen to 15 years in prison on espionage charges, Russian news agencies report.
Businessman Gene Spector was already serving a three-and-a-half-year sentence, having been originally arrested in 2020 on bribery charges.
Last year, he was also accused of spying. Details of the alleged offences have not been publicly released due to the secretive nature of the case, agencies report, and the trial took place behind closed doors.
Russia has taken a number of high-profile American prisoners in recent times - one of whom, journalist Evan Gershkovich, was released earlier this year as part of the biggest swap deal between the countries for decades.