(Reuters) - A report that connected over 1,000 Russian athletes to a state-run doping system only scratched the surface of a drugs culture that may have touched all the country's Olympians, WADA Director General Olivier Niggli said on Friday.
Niggli described the numbers in Canadian law professor Richard McLaren's explosive report as "frightening" but likely do not reveal the full scale of a deep-rooted, institutionalized doping programme operated by Russia.
"Richard McLaren and his team only had access to a fraction of what probably happened in Russia," Niggli told Reuters in a phone interview. "It is very limited compared to probably reality and McLaren said so himself.
"We have to be realistic . He got a sample of what was going on, the scale of this might have been bigger than that.
"It could have concerned every athlete in Russia.
"We probably have a very accurate picture but we know he did not get any collaboration from Russia.
"God knows what may be there."
The second part of McLaren's WADA-commissioned report provided more details of an elaborate doping scheme operated by Russia at the 2014 Sochi Winter Games that were outlined in his original report in July.
It said there was a systematic cover-up, which was refined at the 2012 Olympics, 2013 world athletics championships and 2014 Winter Games, and that more than 30 sports were involved in concealing positive doping samples.
Despite the staggering number of athletes and sports involved Niggli said there are currently no plans to dig deeper in the Russian quagmire with yet another investigation but that WADA would react on new evidence of cheating brought to them.
"The sample is large enough to have a very good idea of the system that was in place," said Niggli. "Even if there is more evidence that will not change the big picture which is how this system came into place and how it is operated.
"McLaren clearly says he does not have any other evidence. They looked at all they had.
"If we get further evidence we will address it.
"If Russian athletes start calling us to tell us what is going on we will look into it but at the moment I think we have exhausted the information that was available to us."
Following McLaren's initial report WADA recommended to the International Olympic Committee that Russians be banned from competing at the Rio Olympics.
The IOC rejected an outright ban and instead left it to individual sporting federations to decide.
Niggli said there would be no new calls for Russia to be barred from future competitions including the 2018 Pyeongchang Winter Games.
But Niggli did emphasise that with the Russian Anti-Doping Agency (RUSADA) already ruled non-compliant the country cannot host any international competitions.
However, Sochi is scheduled to stage the bobsleigh and skeleton world championships next year since the city was awarded the event before being found non compliant.
According to Niggli, WADA's first order of business will be dealing with the individual positive tests detailed in the McLaren report.
The report said that among the findings four Sochi gold medallists had samples with physiologically impossible salt readings, while 12 Russian Sochi medallists had evidence of tampering with the bottles containing their urine samples.
"The way forward after this report is first and foremost to deal with the results management of all these cases," said Niggli. "We will follow up with each national federation and the IOC making sure the results management takes place.
"This is not an easy task. These are not the traditional positive tests you have to deal with you have a lot of different kind of evidence that you need to bring together to get the full picture."
Reporting by Steve Keating in Toronto; Editing by Frank Pingue