LONDON (AP) — Britain's information regulator said Saturday it was assessing evidence gathered from a raid on the office of data mining firm Cambridge Analytica, carried out as part of an investigation into alleged misuse of personal information by political campaigns and social media companies.

More than a dozen investigators from the Information Commissioner's Office entered the data firm's central London office late Friday, shortly after a High Court judge granted a warrant. The investigators were seen leaving the premises early Saturday after spending about seven hours searching the office.

The regulator said it will "consider the evidence before deciding the next steps and coming to any conclusions."

"This is one part of a larger investigation by the ICO into the use of personal data and analytics by political campaigns, parties, social media companies and other commercial actors," it said in a statement.

Authorities in Britain as well as the U.S. are investigating Cambridge Analytica over allegations the firm improperly obtained data from 50 million Facebook users and used it to manipulate elections, including the 2016 White House race.

Both Cambridge Analytica and Facebook deny wrongdoing.

Earlier, Information Commissioner Elizabeth Dunham told Britain's Channel 4 News: "We need to get in there. We need to take a look at the databases, we need to look at the servers and understand how data was processed or deleted by Cambridge Analytica."