Sergei Kabanov was convicted of "high treason" by a court in Tver, a city northwest of Moscow, Interfax news agency said.

He was accused of organising a smuggling network to send "products used in the manufacture of Russian army missiles" to a US-based company, according to Russia's security service (FSB).

The FSB said the equipment included components of "Russian ground-to-air missile systems."

It said the equipment had been transferred via Latvia to an American company called Victory Procurement Services, which was "controlled by the US Department of Defense."

It added that the route used to transfer the equipment had been "eliminated."

Kabanov, who was arrested in 2021, will serve his sentence in a penal colony.