Champion jockey Oisin Murphy has been given a three-month ban after testing positive for cocaine.
The 25-year-old Irishman denied wrongdoing and said investigators accepted he had not taken the drug.
It emerged on 1 October that Murphy's A sample was positive following a racecourse test in France in July.
Murphy testified that he had sex with a woman on the eve of racing and later discovered she was an occasional cocaine user.
"I am pleased the commissioners accepted the evidence presented and am hugely relieved to have been cleared of taking cocaine," he said.
Murphy provided evidence from subsequent hair tests that found no trace of the substance.
French racing ruling body France Galop said the penalty "took into account defence and scientific evidence produced by the jockey and his counsel."
Some jockeys previously testing positive for cocaine in France have been given six-month bans.
Murphy, the number one jockey for Qatar Racing, will be banned from 11 December to 11 March inclusive.
"I respect the rules of France Galop, respect their decision and will not be appealing," he said.
"Despite my relief, I regretfully put myself in a situation whereby cocaine has been able to filter into my system through environmental contamination and must live with the consequences. As a professional sportsman I cannot put myself in a similar situation again."
He won this year's 2,000 Guineas on Kameko and retained the British flat jockeys' championship, with the title race finishing on 7 November.
The French racing authority held a medical commission in October and a disciplinary hearing on Wednesday.
The British Horseracing Authority has said it will reciprocate the ban.
"The next three months will give me much time to reflect on my actions, but I will learn from this experience and come back better and even more determined than before," he said.
- Earlier on Friday, Northern Irish jockey Nathan Evans was given a six-month ban after he tested positive for cocaine at York Racecourse on 20 August.
- In another disciplinary panel hearing following a British Horseracing Authority inquiry, former jockey Ryan While was suspended for two years. He was charged with failing to give a sample at Bath races in July 2019 and misleading investigators.
Additional reporting by Frank Keogh