The former executive director of the Russian anti-doping agency (Rusada) who suddenly died of a heart attack eight days ago, had planned to write a book revealing “the true story of doping in Russia” with information covering the last three decades since he began work for a “secret lab”.

The claims were made in The Sunday Times, which also alleged that Nikita Kamaev had unpublished “actual documents, including confidential sources, regarding the development of performance-enhancing drugs and medicine in sport,” plus communications with the Russian Sports Ministry and International Olympic Committee.

Russia is currently banned from track and field competition, and will miss out on Olympic athletics competitions in August if it is not reinstated, after a World Anti-Doping Agency (Wada) commission report accused Rusada of helping cover up doping by top Russian athletes as part of a systematic, state-sponsored programme of drug use. Kamaev resigned from Rusada in December.

The Sunday Times’ David Walsh reported that Kamaev – who died on 14 February, aged 52 – wrote to him in November offering to reveal the information three days after Wada declared Rusada non-compliant.