Frankie Dettori has been suspended from riding for six months after being found guilty of taking a banned substance.
The three-times British champion jockey tested positive following a routine examination at Longchamp racecourse in France on September 16.
French horseracing's governing body France Galop issued the ban following a recent hearing, and the British Horseracing Authority is likely to follow suit.
The 41-year-old's solicitor Christopher Stewart-Moore said the jockey "fully accepts" the ban, which lasts until May 19.
"France Galop have today announced their finding Frankie Dettori has committed a breach of their rules relating to prohibited substances," said Mr 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."
Mr Stewart-Moore said Dettori was "enormously grateful" for the support of his fans, adding: "Racing has been good to Frankie and he knows that his privileged position brings with it responsibility.
"For this reason he is determined to rebuild his reputation when he returns to the saddle. Frankie could make excuses. He has, after all, regularly been tested for prohibited substances throughout his career. He is clear, however, that the responsibility for his current situation lies squarely with him."
The length of the ban means he will be able to return in time for the key Derby and Royal Ascot race meetings.