Classic-winning Godolphin trainer Mahmood Al Zarooni is to face a British Horseracing Authority disciplinary panel hearing after "serious irregularities" were found in samples taken from horses in his care in Newmarket.

Al Zarooni, who won the Ladbrokes St Leger at Doncaster last year with Encke and has trained a whole host of big-race winners since joining Sheikh Mohammed's operation, told the Godolphin website he had made a "catastrophic error".

He said on www.godolphin.com: "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."

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."

The BHA said that on April 9 this year samples were obtained from 45 horses trained by Al Zarooni at Moulton Paddocks Stables and that on Monday afternoon it had received written advice from the Horseracing Forensic Laboratory that upon analysis 11 of the samples had present in them prohibited substances, namely ethylestranol and stanozolol.

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. Gold Cup runner-up Opinion Poll was one of four horses testing positive for stanozolol,

Adam Brickell, Director of Integrity, Legal and Risk for the BHA, said: "Ethylestranol and stanozolol are anabolic steroids and therefore Prohibited Substances under British Rules of Racing, at any time - either in training or racing. Mahmood Al Zarooni has been advised of the analysts' findings and has been visited by an Investigating Officer.

"A Disciplinary Panel inquiry into the analysts' findings will take place at the first available opportunity, confirmed details of which will follow when available."

(Source: britishhorseracing.com)