Russia on Friday formally contested the four-year ban from major sporting events over doping violations that President Vladimir Putin has condemned as “unjust”, the head of its RUSADA anti-doping agency said.

“In accordance with established procedure, today we have sent a package of documents to the World Anti-Doping Agency (Wada). The package contains a notice about disagreement with Wada sanctions,” RUSADA director- general Yury Ganus said here.

Ganus, who has long argued for a major crackdown by Russia against doping cheats, warned that the legal challenge could backfire, however.

Wada has banned Russia for four years from major global events.