Montreal - The World Anti-Doping Agency (WADA) said on Tuesday that it was "compiling strong evidence" of doping with 298 athletes in the immediate line of fire from files and samples retrieved from Moscow's disgraced former drug-testing laboratory.
Those athletes represent 578 of the 2,262 total samples retrieved in Moscow.
"We are another step closer to bringing to justice those who cheated," said Gunter Younger, director of the investigation unit. "There is still a lot of work left."
The data was removed from Moscow for re-testing at a WADA-accredited laboratory outside of Russia.
Providing full WADA access to the Moscow lab's test files was a key condition of Russia's controversial reinstatement last September following a major state-sponsored doping scandal.
WADA said in Tuesday's statement that its Intelligence and Investigations unit has been validating raw data and samples obtained in Russia in January and April and "has begun compiling strong evidence against those who are believed to have cheated".
WADA added that, so far, it had reviewed 150 samples from 43 of those individuals and compiled packages of evidence which have been sent to the relevant governing bodies.
The statement said those bodies have started assessing the evidence "with a view to identifying those cases to take forward as Anti-Doping Rule Violations". It said that, even if federations did not bring forward a case, WADA could.
WADA said it aims to analyse all the priority cases by the end of the year.
While WADA reinstated Russia ahead of the visits of its investigators to Moscow, not all sports bodies have done so. The IAAF, which runs athletics, in June upheld its ban on Russian athletes.