The Estonian Attorney General’s Office says it has arrested a Russian citizen for helping the Russian Federal Security Service prepare a cybercrime against Estonian state institutions. The man in question was detained at a border checkpoint in Narva, when trying to leave Estonia and enter Russia.

The Russian citizen is charged with “nonviolent actions against the Estonian Republic” and “the preparation of a computer crime.” The first charge carries a maximum penalty of 15 years in prison, and the second charge could land him behind bars for up to two years.

The chief prosecutor in the case, Inna Ombler, says Estonia managed to avoid “serious damage,” but refused to reveal any further details about the case.

In 2015, Estonia exchanged former Russian Interior Ministry officer Alexey Dressen, who was convicted of spying for Russia, for Estonian citizen Eston Kokhver, who received a long prison sentence in Russia for acting as an Estonian spy. Kokhver categorically denied the charges, and Estonian officials claimed that he was kidnapped by armed men on Estonian territory and taken to Russia.