Tallinn - Authorities in Estonia have arrested a former high-ranking official in the defence ministry and his wife under suspicion of treason, local media reported on Monday.

The prosecutor's office said Herman Simm collected classified information and passed it on to representatives from another country.

The authorities will not release any details about the case, nor will they say which country hired the alleged spy, Gerrit Maesalu, spokesman for the State Prosecutor's Office, told Postimees Online.

However, citing unofficial information, the Baltic News Service has reported that Simm worked for Russia, making him the first official suspected of treason since Estonia broke away from the Soviet Union in 1991.

"It's a good thing that a crime has been solved and the suspects have been arrested," the Baltic nation's Defence Minister Jaak Aaviksoo told the press on Monday.

Simm's wife, who has also been arrested, has worked as an attorney at the department of police since 1995.

According to Estonia's law, those who are found guilty of treason face three to 15 years in prison.

Working in the defence ministry since 1995, Simm headed the department charged with protecting state secrets. He led a team charged with setting up a security system to protect clandestine state information as Estonia prepared to join the EU and NATO in 2004. (dpa)