Russian officials arrested Michigan native, Paul Whelan in December of 2018 claiming he had a flash drive containing classified information.
The former Marine said he thought vacation photos were on the drive.
A Moscow judge has sentenced Whelan to 16 years of hard labor, in a trial held behind closed doors.
Whelan alleges he was set up by a Russian who owes him $1,400.
The Whelan family said they believe the conviction was a foregone conclusion.
His family calls that sentence especially severe, noting that Whelan just underwent emergency hernia surgery.
The family said that could now open the path for Moscow to exchange Whelan for Russian prisoners or access to diplomatic compounds seized by the U.S..