Ivory Coast defender Toure could face a two-year suspension after the English FA informed City that the player's urine sample had "tested positive for a specified substance".
Arsenal boss Arsene Wenger outlined the circumstances behind Toure's situation on Friday after a telephone conversation with his former player on Thursday.
Wenger confirmed Toure's belief that the failed test emerged after he had taken a slimming tablet belonging to his wife and stated his support for the 29-year-old.
Yaya Toure has also defended his brother, whilst comments from Valere Gouriso have emerged in which he claims to be Toure's agent.
Toure, who was at Eastlands to watch Saturday's 1-0 win over Wigan, has been left out by City while the case is resolved but they hope the rest of football will leave their player in peace.
"The football club has noted public comments by a number of parties connected to Kolo Toure, regarding the ongoing matter of his current suspension," said a statement posted on the club's official website.
"Whilst the club will continue to make no comment on the nature, status and possible outcome of this case until its conclusion, it would like to stress that public statements from such individuals are unhelpful and in some cases untrue.
"The club would like to make it absolutely clear that until comments made by a Mr Gouriso in particular appeared in the public domain, officials of Manchester City knew neither of his existence nor even of his purported connection to Kolo Toure.
"Suggestions that he has spoken to club officials are wholly without foundation."