Godolphin racing manager Simon Crisford has said he is "shocked", after 11 horses from the Godolphin stable tested positive for anabolic steroids.
Mr Crisford said: "This is a dark day for Godolphin. We are all shocked by what has happened".
"His Highness Sheikh Mohammed was absolutely appalled when he was told and this is completely unacceptable to him. We will await the outcome of the BHA inquiry before taking any further internal action", added Mr Crisford.
"Sheikh Mohammed has instructed me to begin an urgent review of all of our procedures and controls. That is already under way and we will take advice from the BHA in completing it."
International horse racing stables Godolphin has said today that their horse Certify will not be taking part in the Qipco British Horseracing Championship, after allegations that 11 of trainer Mahmood Al Zarooni's horses tested positive for anabolic steroids.
In a statement on the website, Godophin said:
Following an inspection of Zarooni's stable by officials from the BHA, traces of prohibited substances were discovered in a number of the horses tested, including Certify.
The BHA has advised that, as a result, the filly will not be allowed to take part in the Qipco 1000 Guineas at Newmarket next month.
Al Zarooni has admitted that he was responsible for the administration of the prohibited substances.
Horse racing trainer Mahmood Al Zarooni has admitted he has made a "catastrophic error", after samples taken from 11 horses in his care in Newmarket tested positive for anabolic steroids. Al Zarooni said on the Godolphin website:
I deeply regret what has happened. I have made a catastrophic error. Because the horses involved were not racing at the time, I did not realise that what I was doing was in breach of the rules of racing.
I can only apologise for the damage this will cause to Godolphin and to racing generally.
Classic-winning Godolphin trainer Mahmood Al Zaooni is to face a British Horseracing Authority disciplinary panel hearing after samples taken from 11 horses in his care in Newmarket tested positive for anabolic steroids.
Al Zarooni, who won the Ladbrokes St Leger at Doncaster last year with Encke, as well as the richest race in the world, the Dubai World Cup, with Monterosso, trained a whole host of big-race winners since joining Sheikh Mohammed's operation.