LONDON — The U.K.'s information and data privacy regulator is investigating whether Facebook responded "robustly" to reports that political data firm Cambridge Analytica gained access to data on 50 million of its users.
"We are looking at whether or not Facebook secured and safeguarded personal information on the platform and whether when they found out about the loss of the data, whether they acted robustly and whether or not people were informed," Information Commissioner Elizabeth Denham told the BBC on Tuesday morning.
Denham first demanded access to the data held by Cambridge Analytica on March 7, the Information Commissioner's Office said in a statement. The company didn't respond by the deadline given and on Monday evening Denham announced that the ICO is seeking a warrant for the information. She did not say when regulators had started looking into Facebook.
Facebook had started its own audit at Cambridge Analytica's London office, but halted it at the request of the Information Commissioners Office, the company said Monday. The ICO said that Facebook's search "would potentially compromise a regulatory investigation."
Related: Facebook suspends Cambridge Analytica, which worked for Trump campaign
On Saturday, the New York Times and London's Observer reported that the firm harvested private information from more than 50 million Facebook users to influence voters during the 2016 election.
"We are looking at whether or not there was sufficient consent for individuals to be able to share their data with the application in the first place," Denham said.
The probes of the two companies are part of a larger investigation by the regulator into the use of personal data in political campaigns, Denham said.
The British government has called the allegations "very concerning."
"It is essential that people can have confidence that their personal data will be protected and used in an appropriate way," a spokesman for Prime Minister Theresa May said on Monday.
In the U.S., both Democrats and Republicans issued strong statements on Monday calling on Facebook to make changes and questioning whether the company had grown too big, too fast.