A Russian court has granted early release to a 79-year-old former space researcher, Vladimir Lapygin, who was sentenced to prison on a treason conviction and recognized as a political prisoner by the rights group Memorial.

A court in Tver, a city 180 kilometers northwest of Moscow, ruled on June 11 that Lapygin would be released on parole. It is expected this will happen within 10 days, once the court's ruling comes into force.

Lapygin was sentenced to 7 years in prison in September 2016 after a Moscow court found him guilty of handing secret information about the aerodynamic characteristics of hypersonic aircraft to China. Lapygin has denied the allegation saying that he never had access to classified information.

Before his arrest, he worked for a research branch of the Russian space agency Roskosmos.

Since his conviction, Lapygin asked President Vladimir Putin twice to pardon him, but his requests were rejected.

In August 2017, the Moscow-based Memorial human rights group recognized Lapygin as a political prisoner and called for his immediate release.

Lapygin's case is one of several in recent years in which academics have been accused of disseminating sensitive information.

Based on reporting by TASS and Interfax