More than 1,000 Russians - including Olympic medalists - benefited from a state-sponsored doping program between 2011 and 2015, a report claims, BBC informs.

Lawyer McLaren said London 2012 was "corrupted on an unprecedented scale". The report also implicates medallists at the 2013 World Athletic Championships in Moscow and the 2014 Winter Olympics in Sochi.

"It was a cover-up that evolved from uncontrolled chaos to an institutionalized and disciplined medal-winning conspiracy," said Richard McLaren. The report's author said doping took place on "an unprecedented scale"

The report added that the system was refined over the course of the London 2012 Olympics, 2013 Worlds and the Winter Olympics where a now "fail safe" system was in place to protect likely Russian medal winners.

Russia won 72 medals at the London Games, 21 of which were gold, and 33 medals at Sochi 2014, 13 of which were gold.

McLaren’s first report, published last July, detailed how major events in Russia – including the 2013 World Athletics Championships in Moscow and the Sochi Winter Olympics a year later – had been corrupted by the Russian government, the ministry of sport and the FSB who ensured those athletes who were taking banned substances did not test positive in tests, BBC reports.

The report led the World Anti-Doping Agency (WADA) to recommend the entire Russian team be banned from this summer's Games, but the IOC let individual sports decide which athletes should be able to compete.

About 100 Russians were barred from Rio, but the team still finished fourth in the medal table.