The former executive director of Russia’s anti-doping agency, Nikita Kamaev, has died, Tass news agency reports.
His reported death comes two months after he resigned his post at Rusada following the doping scandal which engulfed Russian athletics.
Tass quoted Rusada’s former director general Ramil Khabriev as saying it appeared to have been a heart attack.
Russia was suspended from international athletics last November.
A commission of the World Anti-Doping Agency (Wada) accused Russian athletics of state-backed doping, corruption and extortion in an extensive report.
“It looks like an extensive infraction,” Tass quoted Mr Khabriev as saying.
“He complained of heartache after a skiing session. He has never complained about heart problems, at least to me. Maybe his wife knew about such problems.”
Russia was provisionally suspended from international athletics, including the Olympic Games, in November by the International Association of Athletic Associations (IAAF).
The IAAF took action following the Wada report.
Along with Argentina, Ukraine, Bolivia, Andorra and Israel, Russia was deemed in breach of Wada codes.
Rusada was prohibited from carrying out any Wada-related anti-doping activity.
Mr Kamaev resigned from Rusada in December along with all the organisation’s other top executives as Russia began work on lifting the ban in time for its athletes to compete at the Rio de Janeiro Olympics in August.