Bayern Munich have threatened to report Manchester United to Fifa if they do not give up their pursuit of England midfielder Owen Hargreaves.

The German champions told the English club last week to cease all interest in the 25-year-old Hargreaves.

"Otherwise we will turn to Fifa," Bayern chairman Karl-Heinz Rummenigge told the Munich-based tz newspaper on Tuesday. "A club may only contact a player when the club holding his contract agrees to it."

United manager Alex Ferguson confirmed on Friday that he wanted to bring in Hargreaves, in a bid fill the gap left by Roy Keane's departure. Hargreaves himself has been quoted as saying he would like to move to United.

The midfielder has a contract with Bayern running until 2010.

Newspapers have speculated that United might be prepared to pay €25 million for a player who greatly enhanced his reputation during England's run to the World Cup quarter-finals.

Bayern said they left Hargreaves out of their squad for Sunday's 2-1 win over Bochum in the Bundesliga because of a bout of flu. He will miss tonight's friendly match against Barcelona at the Nou Camp for the same reason.