MOSCOW - A Russian court has convicted a reserve colonel of spying on behalf of the United States and sentenced him to 12 years in prison, the country's intelligence agency said Thursday.

Vladimir Lazar would be sent to a high-security prison and stripped of his military rank, the FSB said in a statement.

Prosecutors alleged Lazar purchased a disk with more than 7,000 images of classified topographical maps of Russia from a collector in 2008 and smuggled it to neighbouring Belarus where he gave it to an American agent.

The agency said the maps could be used for planning military operations against Russia. The FSB did not disclose any personal information or circumstances of Lazar.

The FSB did not specify when the court's verdict and sentence were handed down. The intelligence agency first report charges brought against Lazar in April.

Russian state-owned television broadcast brief footage of Lazar's trial, showing the convict as grey-haired man.