An Estonian court on Wednesday sentenced a former senior security official to more than 12 years in jail for spying and treason in a case that caused deep concern in NATO.
It was the most serious case of espionage since the former Soviet state joined NATO in 2004.
Herman Simm, 61, was arrested last September. He had worked at the Defence Ministry from 1995 to 2006 and had access to top secret documents, including those related to NATO.
A district court said in a statement it had convicted Simm of state treason and passing on classified information. It sentenced him to 12 years and six months in prison.
The prosecutor’s office said last year Simm might have passed information to an officer from Russia’s SVR Foreign Intelligence Service, who had a fake European Union identity.
NATO headquarters was alarmed by the case, local media said, and alliance nations have been looking at the damage caused.