( CNN ) -- Ivory Coast defender Kolo Toure has been suspended by his club Manchester City after testing positive for a banned substance . The 29-year-old , who joined City from English Premier League rivals Arsenal in 2009 , learned of his failed drugs test from the English Football Association ( FA ) on Thursday . `` Manchester City confirm that the FA has informed Kolo Toure that an ' A-sample ' provided by him has tested positive for a specified substance , '' a statement published on the club 's official website read . It continued : `` As result of this , he has been suspended from participating in all first team and non-first team matches pending the outcome of the legal process . `` There will be no further comment from the football club at this stage . '' According to the World Anti-Doping Agency a specified substance is one which could have `` a credible , non-doping explanation . '' Punishments for a positive test range from a warning to a two-year ban from sport . Toure has made more than 50 appearances for City and was captain of the side last season . He is contracted at the club -- where his younger brother Yaya also plays -- until 2013 . Elsewhere in the Premier League , leaders Manchester United manager Alex Ferguson has been charged with improper conduct by the FA over comments he made about referee Martin Atkinson on Tuesday . Following United 's 2-1 league defeat to Chelsea at Stamford Bridge Ferguson told MUTV : `` I must say , when I saw who the referee was I feared it . I feared the worst . He added : `` You want a fair referee , or a strong referee anyway -- and we did n't get that . '' The Scot criticized Atkinson for not sending off Chelsea goalscorer David Luiz for fouls on Wayne Rooney and Javier Hernandez , as well as for awarding what proved to be a decisive penalty late in the match . Ferguson already has a suspended two-game touchline ban hanging over him from 2009 when he said that Alan Wiley was not physically fit enough to referee in the Premier League . A statement on the FA website stated that Ferguson has until next Tuesday to respond to the charge .
Manchester City ban defender Kolo Toure after he tests positive for drugs . Ivorian international could receive a warning or face up to a two-year ban from football . Alex Ferguson charged by FA for comments he made about referee Martin Atkinson . Manchester United manager lashed out at Atkinson after EPL defeat to Chelsea .