Reuters - Russian Olympic bobsleigh champion Dmitriy Trunenkov has been banned from his sport for four years after violating anti-doping rules, Russia's anti-doping agency (Rusada) said on Tuesday.

"The Bobsleigh Federation of Russia, following the materials provided by Rusada disciplinary anti-doping committee, rendered a decision that made athlete Dmitriy Trunenkov ineligible for four years... the period commencing on April 19, 2016," Rusada said.

It did not say what specific violation Trunenkov, who won the gold medal as part of the four-man team at the Sochi 2014 Winter Olympics, had committed.

Russia sent a small team to last year's Rio de Janeiro Olympics following a doping scandal which caused hundreds of its athletes to be banned from competing there.

Russia's athletics federation remains suspended and sports events have been moved away from the country as it grapples with the fallout of a widespread state-backed doping program involving athletes across many sports.

The International Olympic Committee is also re-testing samples from past Games including Sochi, where organisers allegedly switched positive doping samples of Russian athletes with clean ones in order to avoid detection and to give them the edge over their rivals.