Signs for company Cambridge Analytica in the lobby of the building in which they are based on March 21, 2018 in London, England.

The number of Facebook users affected by the recent data sharing scandal could exceed 87 million and records could be stored in Russia, Cambridge Analytica whistleblower Christopher Wylie said on Sunday.

Wylie said that Aleksandr Kogan, whose quiz app harvested the data of tens of millions of Facebook users, could have allowed that data to be stored in Russia. An organization run by Kogan, called Global Science Research (GSR), shared the data with controversial political data analytics firm Cambridge Analytica without their permission.

"I think that there is a genuine risk that this data has been accessed by quite a few people and it could be stored in various parts of the world, including Russia, given the fact that the professor who was managing the data harvesting process was going back and forth between the U.K. and Russia at the same time that he was working for Russian-funded projects on psychological profiling," Wylie told NBC's Chuck Todd during a "Meet the Press" segment.

"I couldn't tell you how many people had access to it, that's a question better answered by Cambridge Analytica, but I can say that various people had access to it."

Facebook and Cambridge Analytica were not immediately available for comment when contacted by CNBC. CNBC also contacted Kogan's Cambridge University email address, but the academic was not available at the time of publication.

Wylie believes the total number of Facebook users whose data was shared could be even more than the 87 million admitted by Facebook last week. Initial reports by the Observer and New York Times newspapers put the figure at 50 million. Cambridge Analytica has said that it licensed no more than 30 million Facebook users from GSR.

You can watch the full NBC interview here.