Vitaly Kaloyev, a 50-year-old architect, was imprisoned in October 2005 after being found guilty of killing Peter Nielsen in February 2004. Nielsen was on duty for Swiss air traffic control company Skyguide when the Russian's wife and two children died in a plane crash in airspace controlled by the company over Germany.
The prosecution has already filed an appeal against the court's decision with the Swiss Federal Court, the country's highest court. Kaloyev could have been released from prison next Friday if the appeal had not been filed.
RIA Novosti does not yet have confirmation of the Swiss news agency's report from the defense or the prosecution.
The Tupolev 154 airliner underwent a midair collision with a Boeing 757 cargo plane on July 1, 2002 over Lake Constance, in Germany, near the Swiss border. All 69 people on board the plane flying from Bashkortostan in the Urals, including 45 children, were killed in the crash. The two pilots from the cargo plane were also killed in the tragedy.