“Officers of the Competition Commission of India searched around 10 locations after it initiated a case against the agencies and top broadcasters over allegedly fixing ad rates and discounts,” said one of the sources.

Three other sources with direct knowledge confirmed the names of the entities being raided.

“The raids were being carried out in Mumbai, New Delhi and Gurugram,” the first source said.

Spokesman for GroupM, Interpublic’s IPG Mediabrands unit, and Dentsu did not respond to requests for comment.

The Indian Broadcasting and Digital Foundation also did not respond, and neither did the competition commission, which does not make public the details of its enforcement action or cases related to price collusion.

WPP-owned GroupM is the world’s largest media buying agency.

The Indian Broadcasting foundation represents top domestic broadcasters, including billionaire Mukesh Ambani’s Reliance-Disney joint venture and Sony and Zee Entertainment.

Reuters was first to report the enforcement action and details of the antitrust case involving the media agencies.