Classic-winning Godolphin trainer Mahmood Al Zarooni is to face a British Horseracing Authority disciplinary panel hearing after samples taken from 11 horses in his care in Newmarket were found to contain traces of 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, has trained a whole host of big-race winners since joining Sheikh Mohammed's operation and told the Godolphin website he had made a "catastrophic error".
He said on: "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."
A statement on the Godolphin website read: "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."
Godolphin racing manager Simon 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.
"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."
Certify, unbeaten in four career outings and winner of the Shadwell Stud Fillies' Mile at Newmarket in September, was one of the seven horses whose sample tested positive for ethylestranol. She had been ante-post favourite through the winter months for the Guineas, and only recently lost that position to Hot Snap.
Gold Cup runner-up Opinion Poll was one of four horses testing positive for stanozolol.