Several whistleblowers have approached the World Anti-Doping Agency (WADA) through a new program set up after revelations of rampant state-sponsored doping in Russia, WADA President Craig Reedie said on Wednesday.
WADA this month launched its "Speak Up" secure digital platform for athletes and others to report anti-doping violations.
"We already have a number of whistleblowers speaking to us, so I am told," said Reedie, speaking at the SportsPro Live conference. He had no details about which sports or countries might be involved.
"The investigations people do not tell the president of the organization what they are doing. And that's exactly the way it should be. That has to be confidential."
Asked whether the world might be facing another big scandal, after Russian track and field athletes were banned from last year's Rio Olympics, Reedie said he did not know but hoped not.
WADA recommended that the entire Russian team be excluded from Rio after an independent report by Richard McLaren, published just before those Games, accused the country of widespread state-sponsored doping.
The IOC rejected a proposed blanket ban and instead let international sports federations decide which athletes should be eligible to compete.
Russia has said it hopes to have the suspension of its anti-doping body RUSADA lifted in November, but Reedie said that could not be relied upon.
He said a decision on Russian athletes' participation at next year's Pyeongchang Winter Olympics in South Korea needed to be made as early as possible and they could expect an aggressive program of targeted testing in the run-up.
"I certainly want (Russia) to be compliant as quickly as possible. Not having the biggest country in the world compliant poses problems for sport that sport is finding very, very difficult to handle," he said.
"What I think is important going into Pyeongchang is that whatever else happens, there is a very rigorous pre-Games testing exercise," he added.
"I think the pre-Games testing program, which is easier to do for a winter Games than a summer Games because you’ve got fewer sports, will almost certainly be extensive and authoritative."
The chances of Russian athletes competing at this year's world athletics championships in London in August remain slim.
"I think it would be difficult for the IAAF to remove the suspension of Russian athletics while the Russian anti-doping agency is non-compliant," Reedie said.
"My guess is that it would be a struggle to have them compliant in time to allow the IAAF to change their view."