Frankie Dettori faces a French horse racing inquiry after a 'positive test' at French track Longchamp in September.
The jockey's solicitor, Christopher Stewart-Moore, said the inquiry, by France Galop, would begin next week.
In a statement, Stewart-Moore said: "As a consequence of a positive test at Longchamp on 16 September 2012, he will be the subject of an inquiry by the medical committee of France Galop."
The British-based Italian, 41, had four rides at Longchamp on that day.
The Sunday meet was a day of major trials for October's Prix de l'Arc de Triomphe meeting.
Dettori rode Marco Botti's Joshua Tree to third in the Qatar Prix Foy, while the John Hammond-trained Sarah Lynx trailed home last in the Prix Vermeille.
He was then beaten by a head into second on Godolphin's Farhh in the Prix du Moulin and was third for his former employers on Willing Foe in the Prix Gladiateur.
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France Galop have not commented on proceedings and in keeping with similar previous cases, they have not issued a statement before the hearing.
Last month Dettori split with Sheikh Mohammed's Godolphin operation after an 18-year association.
The jockey's solicitor, Christopher Stewart-Moore, said the inquiry, by France Galop, would begin next week.
In a statement, Stewart-Moore said: "As a consequence of a positive test at Longchamp on 16 September 2012, he will be the subject of an inquiry by the medical committee of France Galop."
The British-based Italian, 41, had four rides at Longchamp on that day.
The Sunday meet was a day of major trials for October's Prix de l'Arc de Triomphe meeting.
Dettori rode Marco Botti's Joshua Tree to third in the Qatar Prix Foy, while the John Hammond-trained Sarah Lynx trailed home last in the Prix Vermeille.
He was then beaten by a head into second on Godolphin's Farhh in the Prix du Moulin and was third for his former employers on Willing Foe in the Prix Gladiateur.
Play media
France Galop have not commented on proceedings and in keeping with similar previous cases, they have not issued a statement before the hearing.
Last month Dettori split with Sheikh Mohammed's Godolphin operation after an 18-year association.
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