LONDON (REUTERS) - Britain's data protection authority plans to seek a warrant to search the offices on Tuesday (March 20) of London-based political consulting firm Cambridge Analytica, British Information Commissioner Elizabeth Denham told Channel 4 News on Monday.

Channel 4 broadcast secretly taped interviews with senior Cambridge Analytica executives in which they boasted of their ability to sway elections in countries around the world with a menu of digital manipulation and traditional political trickery.

"I think we should all be shocked by this," Denham told Channel 4.

The Information Commissioner's Office is conducting a broad probe into the use of personal data in British political campaigns, which Denham said concerned both Cambridge Analytica, Facebook and 30 different organisations and political parties.

The New York Times and the British Observer newspaper reported on Saturday that the political analytics firm had harvested private data on more than 50 million Facebook users to support Donald Trump's 2016 presidential election campaign.

Cambridge Analytica and its executives did not immediately respond to requests by Reuters for comment.