World Anti-Doping Agency (WADA) president Craig Reedie has said the organization will look into athletes who trained under banned coach Alberto Salazar as part of the Nike Oregon Project (NOP), according to a report in the Times on Tuesday.
Salazar, who counts Britain's Olympic and world champion Mo Farah among the top distance runners he has coached, was last month banned for four years by the U.S. Anti-Doping Agency (USADA) for doping violations.
The USADA investigation found no evidence of any wrongdoing by Salazar's athletes.
"We can look back at what testing these athletes have been subjected to over the years," Reedie told The Times. "But it will be more interesting for us if there are samples we can retest."
According to the report, USADA officials are in the process of sending all of their evidence to WADA's headquarters and The Times understands it would be willing to work alongside the global agency.
USADA chief Travis Tygart told the newspaper in a statement: "We invited WADA to be observers and what they would have seen is that we left no stone unturned. That said, we are happily compiling the evidence and sending it to them."
Salazar, an American who was a celebrated distance runner, winning three consecutive New York City marathons starting in 1980, has vowed to appeal his ban.
Meanwhile, Reedie said on Tuesday that the scale and size of the Russian doping scandal that erupted in 2015 had overwhelmed his organisation at the time.
Speaking at the World Conference on doping in sport, Reedie said the Russian doping affair that emerged ahead of the 2016 Rio de Janeiro Olympics and saw the involvement of a vast number of athletes, coaches and officials was the biggest challenge WADA had faced in its 20-year existence.
"The worst case of system failure in my time as president of WADA or in the entire time of the anti-doping movement is Russia," Reedie told the conference.
He said the level of cheating was "unprecedented," leaving WADA under mounting pressure to work for all clean athletes as the Russian anti-doping agency (RUSADA) was declared non-compliant.
"What it [the scandal] taught us when it erupted was that we were not equipped to deal with such a large-scale programme," Reedie said.
RUSADA was suspended after the 2015 WADA report found evidence of state-sponsored doping in Russian sport and the country was barred from the Rio de Janeiro Olympics the following year.
All Russian athletes also competed as independents at the 2018 Pyeongchang Winter Olympics.
RUSADA's suspension was lifted in September 2018 amid strong criticism as WADA gradually got access to key Russian athletes' data from the Russian lab.
But in September, WADA said it had again opened compliance proceedings against RUSADA after finding "inconsistencies" in the vast bank of historical testing data finally handed over in January.
That means RUSADA are again at risk of being declared non-compliant and thus putting Russia's participation at the Tokyo Olympics next year at risk.
Reedie did not say when a decision on this matter will be taken.
"Clearly we have all faced pressures to deal with the Russian situation effectively," said Reedie, who will be replaced by Poland's sports minister Witold Banka on Jan. 1.
"Athletes expect us in WADA to step up the fight. They expect the rules to be enforced."