A delegation from the World Anti-Doping Agency arrived in Moscow on Wednesday, where they will try to obtain computer data from the laboratory at the heart of a vast cover-up of Russian doping cases.

Russia must provide the data before December 31, or risk having its national anti-doping agency suspended again, two months after its controversial reinstatement.

WADA has found extensive evidence that Russia routinely falsified drug-testing results, including at the 2014 Winter Olympics in Sochi, and hope the country's authorities provide genuine data this time. 

Russia must also submit athletes' stored samples for analysis by June 30. WADA isn't expected to return with the data after Wednesday's visit, which aims to set a procedure for a second team to arrive and collect the files. Any data can be checked against an unauthorized copy of the lab's database, which WADA obtained last year in unclear circumstances. 

If WADA does re-suspend the Russian agency, new rules mean that could severely obstruct Russia's ability to host major sports events. The previous suspension didn't stop Russia from hosting this year's football World Cup when FIFA excluded all Russians from any role in collecting players' drug testing samples.