Russia has exchanged an Estonian who had been convicted of espionage last month for a former Estonian policeman convicted of treason for passing state secrets to Moscow.

The two men were exchanged Saturday on a bridge crossing a river on the countries' border, according to a statement from Russia's Federal Security Service cited by state news agencies.

Estonian Interior Ministry spokesman Tex Vertman confirmed that security officer Eston Kohver had been returned. He was sentenced last month in Russia to 15 years for spying. Estonia claims he had been kidnapped and spirited across the border.

Alexei Dressen, the other man in the exchange, is a former police official who was arrested in 2012 and sentenced to 16 years in prison.