MOSCOW (AP) — A former cybersecurity officer in Russia's Federal Security Service has been sentenced to six years in prison for treason.

Dmitry Dokuchayev's sentencing on Wednesday follows the convictions and longer sentences handed down in February to his superior and to a cybersecurity company executive. Unlike those two, Dokuchayev pleaded guilty.

The trials were held behind closed doors and details of the case remain murky.

Russian media have reported that the case centered on accusations that Sergei Mikhailov, Dokuchayev's boss, and Kaspesky Lab executive Ruslan Stoyanov had passed information on an agency probe of a Russian businessman to an analyst allegedly tied to the FBI.

Mikhailov was sentenced to 22 years in February, and Stoyanov to 14 years.