Updated

A former security official in Estonia has been convicted of treason and will spend 16 years in prison, while his wife received a suspended six-year sentence for treason as well as helping her husband carry out the crime, a court announced Tuesday. Prosecutors allege the couple's actions aided Russia.

The verdicts were announced by the Harju County Court, which tried Aleksei Dressen, a former veteran security police official working with Estonia's Interior Ministry, and his wife, Viktoria.

The trial was closed to the public and the media, and the court did not say who 43-year-old Dressen had given sensitive government information to. But prosecutors said Dressen and his wife, who was not a government employee, were suspected of passing along the material to Russia's main security agency, the FSB, over several years.

Later Tuesday, prosecutor Heili Sepp said a plea bargain was involved and that the court would publish details of Dressen's sentence within two weeks.

"To our knowledge, this is the harshest punishment meted out in plea bargain proceedings in Estonia," Sepp told reporters.

Aleksei and Viktoria Dressen were arrested at Tallinn Airport in February as she was boarding a flight to Moscow.

Prosecutors said that Aleksei Dressen — who had access to documents considered state secrets — went to the airport to give his wife a folder that contained classified information. She allegedly acted as a courier between her husband and the FSB.

Estonian security police head Raivo Aeg said Tuesday that the FSB made initial contact with Aleksei Dressen back in 1998.

Estonia is extremely distrustful of its big eastern neighbor Russia. Security officials and politicians claim that Russia's intelligence community has increased its espionage activities substantially in the Baltic states — Estonia, Latvia and Lithuania — since the three countries joined NATO and the European Union in 2004.

Dressen's conviction is the second high-profile spy case in Estonia in recent years. In 2009, one of Estonia's top security officials, Herman Simm, was sentenced to 12 1/2 years in prison after being convicted of treason for passing domestic and NATO secrets to Russia in a case that shocked the tiny nation of 1.3 million

The case turned out to be one of the most damaging in the history of NATO.