A Chinese man, Tun Sheniyun, faces a charge in Russia of attempted spying for allegedly attempting to gain details of a missile system through bribery.
He was arrested in Moscow in 28 October last year while working as an interpreter.
His arrest was however kept secret from the media until now.
He allegedly sought technological and repair documentation on the Soviet-era S300 surface-to-air system.
Mr. Tun is thought to have been acting on the instructions of the Chinese state ministry.
He formally worked as an interpreter for official delegations.
There was no immediate reaction to the news from Chinese officials.