Captured Estonian intelligence official Eston Kohver was trying to obtain Russian state secrets before he was arrested by Russian authorities, court documents in Moscow show.

Tallinn says Kohver, 44 was captured in Estonian territory earlier this month by members of Russia's secret service FSB after investigating a case of cross border crime.

Moscow, however, say Kohver was carrying out espionage activities. Russian media showed video reports of Kohver being led to a detention center in Russia. A handgun, 5,000 euros of cash and a mission brief was found on Kohver at the time of his arrest.

The secret agent is now being held in a Moscow prison awaiting court proceedings. If found guilty, he could face up to 20 years in prison, his lawyers say.

Estonian officials earlier appointed famous Russian lawyers Mark Fegin and Nikolai Polozov to defend his case. The lawyers became famous after defending Russian punk group Pussy Riot. However, the lawyers were later waived by Kohver prompting Estonian officials to say the case had been meddled with.

Now Russia's FSB claims Kohver had met with one its agents V.V. Ivanov before recruiting him. Ivanov also received cash installments during the meetings at the Estonian- Russian border.

The court documents further accuse Kohver of trying to gain access to classified Russian state secrets. The FSB further claims Kohver allegedly had obtained information on certain individuals cooperating with Russia.

However, Estonia's Security Police (KaPo) have said Kohver was investigating a case of cross border crime before his arrest. KaPo added that Kohver was taken by force in to Russia from Estonian territory during the incident on September 5, Postimees Online reports.

KaPo spokesman Harrys Puusepp said: "We do not have anything to add to that. We will not comment upon FSB's version and the details of the indictment."