Ramon Calderon, the Real Madrid president, insists Manchester United have "no evidence" that the Spanish giants have acted inappropriately in their pursuit of Cristiano Ronaldo.

Fifa confirmed yesterday they had received an official request from United to investigate the matter with the English club claiming Madrid have carried out a deliberate campaign to unsettle the 23-year-old Portugal winger, currently playing at Euro 2008.

But Calderon is adamant his club have no case to answer. "They don't have any evidence because nothing has happened," he said. "All there is is what the papers say and rumours that the player seems to want to leave. But at the moment a move is impossible because United don't want to sell him.

"It's United's right [to complain] but we haven't done anything and we are not going to do anything. It's a matter between the player and his club."

Bernd Schuster, the Real Madrid coach, has denied that the Spanish club are "obsessed" by Ronaldo. The German told the Spanish press that he will not let the issue overshadow his preparations for next season.

"This Cristiano matter does not worry me nor am I obsessed by it," he told Spanish newspaper, Marca. "While he doesn't play for Madrid all we can do is hope, although it's clear that he would be a great signing and would adapt well to our squad."

Fifa's regulations say one club has to inform another if they are to start negotiations with one of their players, although they do not stipulate any possible sanction.

Karim Benzema, the Lyons forward, has added to Sir Alex Ferguson's woes by admitting he would prefer a move to Madrid over Manchester. The Ligue 1 player of the year, who is currently with the France squad at Euro 2008, has long been linked to United.

He told Marca that a move to Spain is something that would interest him in the future. "I like Real Madrid, but I think that I'm still too young to sign for a club like that," he said. "I think that I need to get more experience and I'd like to help Lyons be a European champion. Then, in the future, we'll see what happens."

Benzema signed a contract extension in March to keep him at the French club until 2013, with an option of increasing the deal for a further year.