Manchester City defender Kolo Toure failed a drug test because he took a diet supplement belonging to his wife, Arsenal manager Arsene Wenger said Friday.
Toure was suspended by the Football Association on Thursday after testing positive for an unidentified banned substance, and faces a maximum suspension of two years.
Wenger said he has spoken to the former Arsenal center back and does not believe Toure took a performance-enhancing drug.
''He wants to control his weight a little bit because that's where he has some problems and he took the product of his wife. That's why he was caught,'' Wenger said. ''He was not cautious enough.''
The 29-year-old Ivory Coast international was informed by the FA that he tested positive for a ''specified substance'' after the Manchester derby on Feb. 12. Toure was suspended ''pending the outcome of the legal process.''
Neither City nor the FA have said which banned substance was found in Toure's sample. The World Anti-Doping Agency defines a specified substance as one that is ''more susceptible to a credible, non-doping explanation.''
The punishment for such an offense can range from a warning to a two-year ban.
Wenger knows Toure well from the player's seven-year spell at Arsenal and said he doesn't ''suspect him at all to have taken drugs to enhance his performances.''
''I had Kolo Toure here for years, I brought him here,'' Wenger said at a news conference in London. ''He is a boy who has a clean life, very honest living, always at home, a family man.
''I just think it is a mistake by forgetting to ask, 'Can I take that?'''
Toure has until Wednesday to decide whether he wants his backup ''B'' sample tested.
Scottish player Simon Mensing, who plays for Hamilton, recently served a monthlong ban after testing positive for methylhexaneamine, a stimulant found in diet supplements.
The substance has been behind a spate of recent doping cases, including those of the South Africa rugby players Bjorn Basson and Chiliboy Ralepelle on the Springboks' tour of Britain in November.
WADA recently loosened the classification of methylhexaneamine to the ''specified stimulant'' list, which covers drugs that are more susceptible to inadvertent use.
In another recent doping case in British football, former Sheffield United goalkeeper Paddy Kenny tested positive for the stimulant ephedrine and was suspended for nine months.
Kenny's defense, that the drug was present in cough medicine, was dismissed.
Toure joined City from Arsenal for 14 million pounds (then $23 million) in 2009 and was captain under former manager Mark Hughes before losing the armband to Carlos Tevez for this season.
His brother Yaya Toure also plays for City.
