The World Anti-Doping Agency says it has obtained a database that confirms in effect that the McLaren report, which concluded that more than 1,000 Russian athletes across over 30 sports benefited from state-sponsored doping between 2012 and 2015, is accurate.

The information, obtained by Wada’s investigations team from a whistleblower, is a massive breakthrough in the investigation into Russian doping and casts serious doubt about the country’s participation in the 2018 Winter Olympics in Pyeongchang in February.

Wada said it was still analysing the database, which contains all the testing data at the Moscow Laboratory between January 2012 and August 2015, but confirmed it would be shared with two International Olympic Committee investigations into Russian doping that are due to report within the next month. More revelations are also expected when Wada’s Foundation Board meets in South Korea next Wednesday and Thursday.

With Wada’s Foundation Board likely to conclude that Russia remains non-compliant, the latest revelations further increase the pressure on the IOC, which will make its decision on Russia’s participation in the Winter Olympics on 5 December.

In statement Wada confirmed that by cross-referencing the new intelligence with the McLaren investigation’s findings in June and December 2016, it had “reinforced” its evidence base.

“Wada continues to stand firmly behind the outcomes of the agency’s independent McLaren investigation,” said Wada president Craig Reedie. “This new intelligence serves to reinforce our requirement of Russian authorities that they too publicly accept the outcomes; so that, we can all move forward in rebuilding public trust and confidence in Russian sport.”

The latest revelation comes only days after an internal Russian investigation blamed Grigory Rodchenkov, the former Moscow Laboratory director who turned whistleblower, for its doping problems. Russia has always denied state-sponsored doping.

However last December Richard McLaren said that he had found “a cover-up that operated on an unprecedented scale” – and pointed the finger at the Russian ministry of sport, the Russian security services, and the Russian anti-doping agency for creating what he called “an institutional conspiracy across summer, winter and Paralympic sports”.

The Canadian law professor also said that he had also been able to confirm that urine samples, which had been taken from Russian athletes at the 2014 Winter Olympics in Sochi and at other major championships, had been swapped for their clean urine by using small metal rods to prise open the supposedly tamper-proof bottles. They were carried out by the state security service, the FSB, with McLaren describing them as “magicians”.

Those clean samples were treated with salt and coffee to alter their consistency, tests on which showed in some cases that “samples had salt readings that were physiologically impossible”.