A Russian engineering professor convicted of passing military secrets to China has died in prison.
The federal prison service said Yevgeny Afanasyev, 62, died of a heart attack on April 11 at a prison in the central Ulyanovsk region, where he was serving a 12 1/2 year term on a treason conviction.
Afanasyev, a professor at the Voyenmekh Baltic State Technical University in St. Petersburg, was convicted of treason in 2012.
He and a fellow professor, Svyatoslav Bobyshev, was arrested in 2010 and accused of handing Chinese intelligence classified information on the Bulava, a submarine-launched ballistic missile Russia has been testing in recent years.
The men had lectured at China's Harbin Technical University as part of an exchange program.
Bobyshev was sentenced to 12 years for "complicity in treason."
Several test launches of the Bulava, which Russia says has a range of 8,000 kilometers and can be equipped with 10 nuclear warheads, have failed.
The missile was last successfully test-fired in November.
Based on reporting by RIA, Interfax, and AFP