An elderly Russian university professor has been arrested for treason after he allegedly passed on classified information to a NATO country, and is being held in jail despite his ill health.

Professor Valery Golubkin, who lectures at the Moscow Institute of Physics and Technology (MIPT), was arrested by the Russian authorities for treason on 13th April.

He is a colleague of the physicist Anatoly Gubanov, who, according to local media, “partially admitted” his guilt for treason during questioning by the authorities in December last year.

The two men are involved in aircraft design, and co-authored a scientific paper on supersonic speeds. Despite the similar charges against the two men, their cases are reportedly unlinked.

The Russian authorities accuse Golubkin, 69, of passing on classified information related to the development of ‘high-speed experimental fly vehicles’ to an unspecified NATO country.

However, the MIPT has claimed the scientist, who teaches fourth-year students ‘high-speed aerodynamics’ on a part-time basis, did not have access to state secrets.

Local media report that Golubkin, who was treated for cancer in 2015, suffers from hypertension and is in poor health generally.

Despite his ill health, he is being held in preventive detention until 12th June. If found guilty, he could face from 12 to 20 years in prison.

The number of alleged treason cases has dramatically increased in Russia in recent years, with academics, along with military personnel, former intelligence officers and journalists, often on the receiving end.

The investigation into Golubkin, who maintains his innocence, continues.