(CNN) The top Democrats on the Senate and House intelligence committees said this week that Facebook's relationship with a Russian internet conglomerate warrant further scrutiny.
Sen. Mark Warner and Rep. Adam Schiff were commenting on a CNN report published Tuesday detailing how the Mail.Ru Group, a company with ties to the Kremlin, developed applications that allowed it to gather data on Facebook users without their explicit knowledge.
Schiff told CNN's Wolf Blitzer on "The Situation Room" Wednesday that his committee was not aware of the company's access to Facebook data before it was reported by CNN.
He expressed concern that data accessed by Mail.Ru could have been obtained by the Russian government, saying, "if the Kremlin take interest in data of any Russian company has, those Russian companies are not in a position to say 'no.'"
Warner told CNN in a statement on Tuesday, "Now we learn that the largest technology company in Russia, whose executives boast close ties to Vladimir Putin, had potentially hundreds of apps integrated with Facebook, collecting user data. If this is accurate, we need to determine what user information was shared with mail.ru and what may have been done with the captured data."
Facebook apps have attracted scrutiny after it was widely reported earlier this year that an app developer working for Cambridge Analytica in 2014 built an online survey that gathered and harvested data on tens of millions of Americans, most of whom had never downloaded or taken the survey. Cambridge Analytica went on to work for Donald Trump's 2016 presidential campaign.
The Mail.Ru Group built hundreds of Facebook apps, Facebook confirmed to CNN on Tuesday.
The company says it has found no evidence that the Mail.Ru Group had misused Facebook user data but acknowledged that the investigation is continuing and would not answer if Facebook even has the ability to determine how the Russian company used data derived its platform.
The Mail.Ru Group told CNN it acted in accordance with Facebook's terms and conditions and said it "never harvested any data" from Facebook.
Mail.Ru Group is controlled by USM Holdings, a company founded by Alisher Usmanov, who was included on a list the US Treasury Department published in January of Russian billionaires with ties to the Kremlin.
Russian investor Yuri Milner was the chairman of Mail.Ru Group until he stepped down in 2012. Milner told Forbes he served as a member of then-Russian President Dmitry Medvedev's innovation commission from 2009 to 2011.
The New York Times reported last year that Milner invested in Facebook and Twitter with hundreds of millions of dollars from Russian state institutions funneled through offshore shell companies, though Milner's companies have since sold those holdings. In interviews for that report, Milner said the Russian government money was no different from other international investments, and he said he focuses on business and philanthropy, not politics.