The former head of Russia's anti-doping agency Rusada has died, the organisation says.
Nikita Kamaev's death comes two months after he resigned his post following a doping scandal in Russian athletics.
Rusada said the cause of death was "a massive heart attack".
Russia was suspended from international athletics last November. The World Anti-Doping Agency (Wada) accused Russian athletics of state-backed doping, corruption and extortion.
"He will remain in our memories as an experienced and understanding leader, distinguished by his high professionalism," the Rusada statement said, adding that Mr Kamaev, 52, was able to create a "friendly atmosphere" in his team.
His death comes just two weeks after that of Rusada founding chairman, Vyacheslav Sinev.

путинский режим сегодня, как Титаник после Столкновения с Айсбергом. Пассажиры продолжают веселиться, но судьба Титаника уже предопределена.