Richard McLaren, the Canadian lawyer whose 2016 bombshell report exposed state-sponsored doping in Russia, suspects "hundreds" of doping cases could be contained in the latest data retrieved from Moscow.

On Thursday, WADA said they had "successfully retrieved" data from the Moscow laboratory at the heart of the affair.

"It's pretty much anyone's guess as to what that number is," McLaren said when asked how many doping cases he expected the new data to reveal.

"My thinking would be in the 300-600 possible range."

WADA had demanded the data be handed over to complete its probe into the 2011-2015 scandal which eventually saw Russia's athletics team barred from the 2016 Rio Olympics and exiled from the 2018 Winter Olympics.

In September, WADA conditionally lifted a ban on the Russian Anti-Doping Agency (RUSADA), paving the way for its reinstatement.

One of the conditions was access being granted to the data by the end of 2018.

But when a WADA team arrived last month, Russian authorities raised issues with the certification of their equipment under Russian law and a December 31 deadline was missed.

"It's puzzling to go back and think, what went on in December that they weren't prepared to provide information and some ten days later in January, they are," McLaren, who is no longer involved in the investigation, told German broadcaster ARD on Friday.

"I think what was going on there was nothing to do with WADA, but it was a power struggle within Russia.

"That got resolved over the Christmas period and now they are preparing to provide the information and are in the process of doing so."

WADA will now attempt to authenticate and review the data "and my hope would be that they get the complete and true data," McLaren said.

"Some of it will have to be cross-checked and analysed to determine it's authenticity in a number of steps, that won't happen in a couple of days -- it could take two or three weeks.

(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)