Kolo Toure was banned for six months in 2011 after failing a drugs test while at Manchester City.
Liverpool defender Kolo Toure pledged his support for teammate Mamadou Sakho after it was revealed the Frenchman failed a drugs test.
Sakho tested positive for a banned substance after the 1-1 draw against Manchester United in the Europa League on March 17 and could face a lengthy ban.
While the 26-year-old is not formally suspended at this stage, he will not be considered for first-team duty until the matter is resolved - a decision taken by the club in conjunction with the player - with Liverpool likely to request the testing of a B sample.