Posted 22 April 2013, 18:30 GMT

Godolphin trainer Mahmood Al Zarooni is to attend a British Horseracing Authority (BHA) disciplinary inquiry after serious irregularities were found in samples taken from horses in his care at Moulton Paddocks, Newmarket.

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 1,000 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 underway and we will take advice from the BHA in completing it."

Al Zarooni said: "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."

No further comment will be made pending the completion of the BHA investigation and inquiry.