Mutu, 31, tested positive for sibutramine after scoring in his side's 2-1 home win over Bari in the league on January 10. He risks a suspension of between one and four years. In a statement, the Tuscan club said their medical staff had had nothing to do with the administration of a banned substance and expressed their belief in "the good faith" of the player.
The club added that they wanted to see "the affair cleared up as quickly as possible". Sibutramine is a medicine principally used in the treatment of obesity. According to the ANSA news agency, who spoke to a pharmacologist, the substance would enable an athlete to increase his level of aggression. Media reports in Romania on Friday, meanwhile, speculated that Mutu could have accidentally been given the drug by his mother.
Interviewed by the TV channel Telesport, Mutu's mother, Rodica Mutu, admitted to having taken slimming tablets and said she had "definitely left some of them in Italy" while visiting her son. "Maybe he took them out of curiosity as I had boasted about losing weight," she said. "But in any case, the box says that they're a natural product that contains no banned substances."
Friends and relatives have rallied round the star, asserting that he would not have taken doping products on purpose. Mutu was fired by Chelsea after a positive test for cocaine in 2004, not long after joining the English Premier League club. He subsequently served a seven-month ban for use of a banned substance.