World soccer's governing body FIFA said on Monday it would look into a complaint from Manchester United concerning Real Madrid's alleged attempts to unsettle winger Cristiano Ronaldo.
United threatened to take Madrid to FIFA last month after club officials were quoted expressing their admiration for the Portuguese player, who is representing his country at Euro 2008.
On Monday FIFA confirmed receiving a formal complaint from the English Premier League side.
"It is too early to say how the matter will be dealt with," FIFA spokesman Pekka Odriozola said. "We will first have to look at the precise nature of the complaint before seeing what steps will be taken."
United claim that Madrid's statements about Ronaldo are aimed at tempting the player to breach his contract.
Real Madrid have denied any wrongdoing.