Manchester United have made a formal complaint to FIFA over Real Madrid's public pursuit of Cristiano Ronaldo.
Last month the Red Devils warned the Spanish club they would contact the world governing body should they continue to make statements revealing their admiration and desire to sign the Portugal international.
United were adamant that the 23-year-old winger was not for sale at any price, but Ronaldo himself has since refused to pledge his future to the club.
However, with speculation over the player's future intensifying while away on international duty at Euro 2008, United have followed through on their threat to take the matter to FIFA.
"On 27 May, Manchester United made clear its intention to report Real Madrid to FIFA if it continued to involve itself in the future of Cristiano Ronaldo," read a club statement.
"Unfortunately, Real Madrid has not kept its own counsel and the club feels it has no alternative but to make a formal complaint to the world governing body, which it has done today.
"The precise content and nature will remain confidential."