Russia's Investigative Committee has concluded that all materials submitted to the World Anti-Doping Agency (WADA) this year regarding athletes' drug tests were genuine, contrary to WADA's determination that the copy it received of a database from Russia's national drug-testing laboratory was intentionally altered.

WADA's finding was key to its December 9 decision to declare the Russian Anti-Doping Agency (RUSADA) noncompliant, and to ban Russia from major international sporting competitions for four years.

Russia is currently considering an appeal of the ban and is weighing its legal options.

The database, which includes Russian athletes' blood-test results and other information stored by the national anti-doping laboratory in Moscow, is at the center of the exposure of Russia's state-sponsored doping program.

The program was revealed when whistle-blower Grigory Rodchenkov, who formerly headed the Moscow lab and was one of the architects of Russia's elaborate doping and cheating system dating back to 2014, provided a copy of his lab's database.

Extracting a second copy of the database as well as samples from the laboratory was a major condition set by WADA when it reinstated RUSADA in September 2018 following earlier sanctions. The lab samples had been stored and sealed off by Russia's Investigative Committee as part of its probe into Rodchenkov.

Russia was given a deadline of December 31, 2018, to hand the data over, but missed the deadline. In mid-January, WADA did receive a copy of the database, but a review of the information revealed "inconsistencies" that required clarification. In April, Russia allowed WADA to retrieve all blood samples from the lab and provided answers to WADA investigators' questions.

"The investigation carried out a comprehensive computer-technical forensic examination of copies of the transferred electronic files, the results of which made a conclusion about their authenticity, as well as the absence of distortions of the original file structure of the test results of Russian athletes," Investigative Committee spokeswoman Svetlana Petrenko said on December 21.

Russian authorities have claimed that the database was intentionally accessed and altered by Rodchenkov as part of a criminal conspiracy and have previously argued that the differences between the two database copies were the result of the lab's database system malfunctioning.

Lawyers for Rodchenkov -- who currently lives under witness protection in the United States, where he fled in 2016 after handing over the database -- have said that Russia's efforts to falsify data given to WADA is part of a "predictable and deplorable policy of deception."

On December 21, Investigative Committee spokeswoman Petrenko repeated the Russian allegations against Rodchenkov, adding that the "truth of the information" contained in the lab data provided by the whistle-blower "has not been determined."

In issuing its ban on December 9, WADA stated that the data it received from Moscow was "neither complete nor fully authentic."

Some data was "removed, others altered and, in some cases, system messages were fabricated in an effort to hamper the work of WADA investigators," the world doping watchdog said. "In addition, measures were taken to conceal these manipulations by back-dating of computer systems and data files in an attempt to make it appear that the Moscow data had been in their current state since 2015."

The ban imposed by WADA on December 9 was just the latest punitive action taken against Russian sport related to the exposure of the state-sponsored doping program, which Russia has never acknowledged.

Team Russia was barred from competing at major sports competitions, including the 2016 Olympic Games and the 2018 Winter Olympics. It now stands to be left out of the Olympics in Tokyo in 2020 along with other major events.