Real Madrid have begun legal action against French newspaper Le Monde following an article published last week alleging the club had links to Spanish doctor Eufemiano Fuentes.
Fuentes, who is being investigated in a judicial inquiry into doping in sport, did not name the clubs he has worked with in an interview with Le Monde.
Real published a copy of a letter sent to Le Monde on their website.
It read: 'The title of the article is false for Real Madrid have never been linked to doctor Eufemiano Fuentes. It is also false that our club has ever requested the services of this doctor.
'No unauthorised product or substance has ever been used within our club. Equally false is the notion that any of our players ever scheduled appointments with said doctor.
'Thus, all reports and data published are emphatically false.
'Taking into account the falsehood of the information published by your journal, we invite and demand to rectify all these false reports and that this rectification and subsequent apology be published in the same manner and layout format as the above mentioned original article with its false allegations.
'In any event, we wish to inform you that Real Madrid (notwithstanding the legal actions that other incriminated parties may incur) will file the appropriate lawsuit against your newspaper and the person or persons directly or indirectly responsible for the fabrication and publication of said false and untrue reports.'