Russian athletes remain suspended for the World Athletics Championships in Doha, the IAAF has confirmed.
Russia had missed deadlines to hand over the data before finally granting Wada access to the Moscow anti-doping laboratory in January.
BBC Sport understands that senior Wada officials were briefed last month that the organisation’s experts had found evidence some data may have been manipulated before being passed over to an inspection team.
Sir Craig Reedie, president of the International Olympic Committee, described the development as “disappointing but not an embarrassment”.
“The whole point of the exercise was to get access to the information so that we could then put together cases that international federations could prosecute against people that have been cheating,” he added.
“We’ve now found some inconsistencies, we’re going to deal with it, we’re going to deal with it properly.”
Rob Koehler, a former Wada executive who now heads up Global Athlete, a group that has been critical of the global watchdog’s handling of the crisis, said athletes are “furious” with Wada.
“The time has come to demand resignations from Wada’s leadership because they have shown they are not fit for purpose.
“I hope I, along with the athlete community, am proven wrong, but this entire ordeal will play out in favour of Russia as it has done all along with no meaningful consequences.”
A Wada-commissioned report in 2016 found Russia operated a state-sponsored doping programme for four years across the vast majority of Olympic sports.
Russia was told it had to meet two criteria before Rusada could be reinstated after a three-year suspension: accept the findings of the McLaren report into state-sponsored doping, and grant access to Moscow’s anti-doping laboratory.
However, Wada’s stance softened, and after offering a compromise over the ‘roadmap’, its compliance review committee (CRC) controversially recommended reinstatement in September 2018 before the second condition had been met, prompting fury from many athletes and anti-doping organisations.
In December, Russia missed a deadline to grant access to its lab, but the following month an inspection team was finally allowed to retrieve the data.
Although it was accused by many of being too soft on Russia, Wada’s leadership hailed the breakthrough, insisting it would enable it to identify potential cheats, and allow international federations to pursue cases against them.
CRC chairman Jonathan Taylor – a British lawyer – also warned that if the data was found not to be authentic, he would “propose serious consequences”.