Frankie Dettori has been suspended from riding for six months after being found guilty of taking a prohibited substance, his legal representative Christopher Stewart-Moore said on Wednesday morning.

The three-times British champion jockey, 41, tested positive for what is believed to be cocaine following a routine examination at Longchamp on September 16.

Dettori's suspension runs from November 20 to May 19 and is likely to be reciprocated by racing jurisdictions worldwide, including by the British Horseracing Authority.

Stewart-Moore said in a statement released to Press Association that Dettori "fully accepts" France Galop's decision to ban him for six months.

"France Galop have today announced their finding Frankie Dettori has committed a breach of their rules relating to prohibited substances," said Stewart-Moore.

"I have spoken to Frankie since the announcement was made and he has told me he fully accepts France Galop's decision.

"He also accepts that he has let down the sport he loves and all those associated with it, as well as the wider public. But most of all, and this is his greatest regret, he has let down his wife and children."

France Galop said in a statement that Dettori must be retested by an appointed doctor "no sooner than April 20" next year, and confirmed it had requested the suspension extends to other racing authorities worldwide.

The statement read: "On Tuesday December 4, the Stewards of France Galop conducted a cross-examination of jockey Lanfranco Dettori's file in the presence of his solicitor Mr Christopher Stewart-Moore and his representative M. Herve Naggar.

"In the present conditions and considering this case represents a serious violation to the Rules of Racing, the Stewards of France Galop have issued the jockey with an authorisation to submit to a new medical examination no sooner than April 20, 2013."