The former head of a Russian rocket technology firm who was jailed in 2007 for selling state secrets to China has been released on parole, Radio Liberty reported.

Igor Reshetin, the former director of TsNIIMASH-Export, was sentenced to 11-and-a-half years - later reduced to seven on appeal.

Reshetin's father, Andrei Reshetin, told the radio station on Monday that he already was with his family.

Reshetin was charged with illegally selling state-controlled technology to a Chinese firm and with stealing 30 million roubles ($925,000) through a scheme involving bogus companies.

Several of his colleagues were also jailed.

TsNIIMASH-Export was linked with Russia's state space agency.

Reshetin insists he is innocent, and rights groups have said his conviction was trumped up, a claim denied by the authorities.