MOSCOW, December 7. /TASS/. The Russian Federal Security Service (FSB) has classified all documents in the criminal case of high treason against geodesy scientist Valery Kachin, who was taken from Birobidzhan to Moscow for further inquiries, the press service of Moscow's Lefortovo court told TASS on Wednesday.

"The materials of the criminal case against Kachin are classified," the agency's source said.

Earlier, it was reported that investigators charged the scientist with high treason.

"In the course of operational and investigative measures, the officers of the Russian Federal Security Service detained scientist Valery Sergeevich Kachin. He was charged with treason (Article 275 of the Russian Criminal Code). A preventive measure in the form of detention was chosen for the accused by the Birobidzhan District Court of the Jewish Autonomous Region. He was transported to Moscow detention center ‘Lefortovo’ for further investigative actions," the source said.

Moscow’s Lefortovo court told TASS that the prosecution has asked that the scientist’s arrest be extended until March 12.

Kachin, 35, graduated from Sholem Aleichem Amur State University. He previously worked at the Bastak Nature Reserve, where he was a junior researcher and specialized in geoinformation systems.