Rupert Murdoch's film and media giant 21st Century Fox says it is cooperating with the European Commission after officials raided its Fox Network offices in London.
The EC competition authorities reportedly seized documents on sports media rights on Tuesday.
Other sports rights companies have also received "unannounced inspections", which the EC refers to as "unannounced inspections".
It is unclear which other companies were looted and when.
"The Commission has concerns that the companies involved have violated EU antitrust rules that prohibit cartels and restrictive business practices," the European Commission said in a statement.
"Unannounced inspections are a first step in the alleged anticompetitive practices."
The statement said, "No means companies have anticompetitive behavior, nor does it prejudge the outcome of the investigation itself."
Sports broadcasts have become a huge business in Europe and the US, with networks spending billions of pounds to get exclusive rights to show games in top leagues to attract viewership.
Fox Networks Group is an operational unit of Fox that distributes TV and cable channels and content worldwide.
"The Fox Networks Group works closely with EC inspection," said a spokesperson.
The move comes in the midst of a revolution of Mr. Murdoch's empire.
21st Century Fox has agreed to sell most of its entertainment assets, including its stake in Sky, to Disney for $ 52.4 billion. But in February, US giant Comcast offered $ 31 billion for Sky.
As part of the restructuring and dealings with Disney, the 21st Century, which seeks 61% of Sky, which does not own it, is trying to buy problems with the UK's competition authorities
The commission said that there was no legal deadline to investigate anti-competitive behavior and that the Commission's investigation could take a long time.