Metsavas was serving as an officer in the Estonian Defence Forces (EDF) at the time the alleged offences, forwarding Estonian state secrets and classified external information to the Russian military intelligence agency, the GRU, were committed, spokespersons for he Office of the Prosecutor General said.

It is suspected that the activities were carried out over a period of five years.

Harju County Court in Tallinn placed the men in custody on Wednesday at the request of Public Prosecutor Inna Ombler, who is leading the investigation.

Press conference announcements

Chief Prosecutor of Estonia, Lavly Perling, stated at a press conference on Wednesday, starting at 13.00 EEST, that one of the suspects is Maj. Deniss Metsavas, staff officer at the combat support department of the EDF headquarters, and the other Pjotr Volin, is his father.

Metsavas had served as an artillery officer in the northeast Estonian defence district. He was due to take up a position with the Kaitseliit (volunteer defence league) from Monday, it is reported.

Commander of the EDF, Gen. Riho Terras, also at the press conference, said that Metsavas had been on active EDF service since 2008 and had succeeded in leaving an impression as a competent and committed officer.

"However, he is a traitor," Gen. Terras added.

Gen. Terras went on to state that the actions of Metsavas and Volin have dealt a significant wound on Estonia's national defence and an emotional blow to personnel working in the EDF.

A committee is to start work immediately, on the orders of Minister of Defence Jüri Luik (Isamaa) to examine the situation with a view to mapping out solutions.

Earlier assertions of Estonian patriotism

In a twist of irony, Metsavas had appeared on a TV talk show in 2016 stating that there were many ethnic Russians serving in the EDF (of which he was one) who are Estonian patriots.

Appearing on the ETV broadcast, 'Vabariigi kodanikud', ('Citizens of the Republic') Metsavas said that ''I do not want to appear too resolute, but Hvostov's [journalist Andrei Hvostov, who had spoken on the show of the loyalty of Russian-speaking Estonian residents and criticized Russia's 'compatriots policy' – ed.] rhetoric is a reminder ... that there is a collection of fantasised people who need to be protected.''

''My mother tongue is Russian, I went to the Lasnamäe Russian Upper Secondary School, so I am not so sure that I would need protection [of Russia] ),'' Metsavas went on in the 2016 broadcast.

Russian speakers in the EDF

Metsavas also stated that his knowledge of two languages, ie. Estonian and Russian, had assisted him greatly in his EDF career.

''There is an issue with having an Estonian and Russian community, but the situation is not all that bad,'' he averred.

"We have a lot of Russian members in the EDF with whom I can communicate more easily. I encounter hundreds of EDF officers who come from [easternmost Estonian county] Ida-Viru County... a lot of great colleagues at Tapa [military base] who are from Ida-Viru County and who feel patriotic about Estonia,'' he went on.

''Compared with 10 years ago, Russian youth is speaking a lot more Estonian, knows the culture and Estonia as a whole, and is much better integrated. They know that there is an Estonian state which needs to be protected,'' he said.

Previous treason cases

In another high profile case, Herman Simm was convicted of treason in 2009 and sentenced to twelve and a half years in prison, for passing on information to the Russian Foreign Intelligence Service (SVR) over a period of nearly 13 years. This year, Simm, 71, appealed for early release but the appeal was rejected.

In September 2014, Estonian intelligence agent Eston Kohver was abducted by Russian agents under disputed circumstances close to the Estonian-Russian border and later sentenced in a Russian court to 15 years in prison for alleged espionage. Two years later, in September 2016, Kohver was exchanged on at a border checkpoint for Aleksei Dressen, who had been sentenced in to 16 years in prison for relaying sensitive information to Russia in 2012.

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