Russia on Wednesday sentenced two professors from an engineering university to 12.5 and 12 years for handing over information about a new intercontinental missile to China, an official said.

"Yevgeny Afanasyev was sentenced to 12.5 years for treason, and Svyatoslav Bobyshev to 12 years in a high-security penal colony for complicity in treason", a court official told AFP.

The two men, both professors at the Voyenmekh Baltic State Technical University in Russia's second city of Saint Petersburg, were arrested in March, 2010 on charges of high treason and espionage.

The Russians had been accused of handing over the information on the Bulava, Russia's latest submarine-launched ballistic missile, to Chinese intelligence.

The intercontinental nuclear-capable missile was developed to replace Russia's Soviet-era stock.

The project suffered numerous failed launches over the past decade but was approved late last year after several successful test firings.

In May, a worker from a Russian weapons plant in the Urals was sentenced to eight years in jail for handing over information on the Bulava to foreign intelligence.