The World Anti-Doping Agency, the global regulator of drugs in sports, said Friday it had obtained a digital trove of information that could greatly expand revelations about Russia’s state-sponsored doping program. The massive scheme has corrupted the results of several Olympics and has imperiled the country’s eligibility for the coming Winter Games in South Korea.

The agency said that its investigations department had been in possession since late October of an electronic file that was long considered a final piece of the puzzle revealing the contours of the doping system. The agency said in a news release that it was confident that the file contained “all testing data” from January 2012 to August 2015 — thousands of drug screenings run on Russian athletes.

“This evidence could be another mother lode and potentially open a new dimension to the gravity of the fraud perpetrated by the Russia doping conspiracy,” Travis T. Tygart, the chief executive of the United States Anti-Doping Agency, said Friday. “Clean athletes expect and deserve justice and the whole truth being brought to light.”

The database, which the Russian authorities were unwilling to share with antidoping investigators, arrived through a whistle-blower, according to two people with direct knowledge of the situation who spoke on the condition of anonymity.