Nikita Kamayev, who headed Russia's scandal plagued anti-doping agency RUSADA until late last year, died of what was believed to be a heart attack while skiing, state news agency TASS reported.

"Sadly Nikita has passed away. What happened looks like a massive heart attack," the former general director of the anti-doping agency, Ramil Khabriyev, was quoted as saying.

"He complained of heart ache after a skiing session. He has never complained about heart problems, at least to me. Maybe his wife knew about such problems," Khabriyev said of the 50-year-old's death.

Kamayev, Khabriev and other management resigned in December after the World Anti-Doping Agency (WADA) issued a damning report accusing Russia of widespread state-supported cheating and corruption in testing standards for athletes.

RUSADA and Moscow's anti-doping laboratory were suspended over the report.

Russian President Vladimir Putin distanced himself from the accusations and called on those responsible to own up to the violations.

Kamayev's death comes as inspectors from International Association of Athletics Federations (IAAF) were scheduled to begin a two-day visit to Russia to review anti-doping reform after the country's athletes were barred from international competitions.

Russia is scrambling to lift the athletics ban before the Rio de Janeiro Olympics in August.

cw/rc (AFP, Reuters)