British racing's governing body has banned trainer Mahmood Al Zarooni for eight years for his role in a doping scandal that has rocked the sport.
Al Zarooni, 37, was given the punishment after a disciplinary hearing, at the BHA headquarters in London, revealed 11 of the horses he trained for Sheikh Mohammed's Godolphin stable had tested positive for anabolic steroids.
"Mahmood Al Zarooni has been disqualified for eight years following today's Disciplinary Panel hearing," a BHA statement on Twitter read.
Samples were taken earlier this month from 45 horses trained by Al Zarooni and subsequent analysis showed 11 of the samples contained ethylestranol and stanozolol, which are prohibited substances.
Sheikh Mohammed reacted to what has been described as racing's biggest doping scandal in recent years by shutting the stables and ordering a full-scale internal investigation.
The sheikh, one of racing's leading figures and the ruler of Dubai, said he was "appalled and angered" by the revelations.
Al Zarooni has said the situation was a "catastrophic error" and claimed that he did not realise he was in breach of racing rules by administering the drugs as the horses were not racing at the time.
The 37-year-old, who was charged on Wednesday with breaching rules "related to prohibited substances, duty to keep medication records, and conduct prejudicial to racing", arrived at the hearing to a crowd of photographers and television cameras but said nothing to waiting reporters.
The BHA said he had told investigators that a further four horses that were not tested were also given the banned substances.
Earlier on Thursday, the BHA handed six-month bans to 15 horses owned and trained by the Godolphin stable.
The bans were backdated to April 9 - the day they were first tested at Godolphin's Newmarket stables in eastern England.