Sources at the location told the newspaper that authorities were trying to be discreet and had been told to keep details of their mission confidential. The Telegraph reported that investigators will be on site through Wednesday and maybe Thursday.
Shares of Fox fell more than 1 percent in extended trading.
The raid comes amid Fox’s drawn out takeover of Sky, which has fallen under intense scrutiny by regulators at the U.K.’s Competition and Markets Authority.
Earlier this year, the agency provisionally found Fox’s bid would not be in the public interest. It said there are concerns that the deal may lead to the Murdoch Family Trust wielding too much influence over public opinion and the political agenda.
Fox Networks Group said in a statement to CNBC that it is “cooperating fully with the EC inspection.”
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