Nikita Kamayev, former head of Russia's Anti-Doping Agency, approached the Sunday Times before his death offering to expose the country's secret development of performance-enhancing drugs, the newspaper has reported.
Ten weeks before he passed away, Kamayev said he wanted to write a book that would reveal the complete extent of doping in Russia, the Sunday Times said in a front-page article.
"I want to write a book about the true story of sport pharmacology and doping in Russia since 1987 while being a young scientist working in a secret lab in the USSR Institute of Sports Medicine," he told the newspaper in an email.
"I have the information and facts that have never been published."
Russia was suspended from international athletics in November after a special commission of the World Anti-Doping Agency (WADA) exposed widespread state-sponsored cheating and corruption.
Kamayev, who quit as executive director of Russia's Anti-Doping Agency (RUSADA) two months ago, died last weekend at the age of 52.
A Taas news agency report said it appeared his death was caused by a heart attack.
Kamayev stood down from his position, along with the rest of the senior RUSADA management, in mid-December as Russia began working on lifting the suspension in time for its athletes to compete at the Rio de Janeiro Olympics in August.