Disgraced trainer Mahmood al-Zarooni was accused by his Godolphin manager on Friday of ignoring repeated warnings from the stable before embarking on a "reckless" program of doping that "betrayed the trust" of British horse racing.

Godolphin racing manager Simon Crisford said al-Zarooni, who was disqualified from racing on Thursday for eight years his part in a major doping scandal, had "tarnished the Godolphin brand so badly that it's going to take a long time to recover."

The warning signs were there for Godolphin when two horses from al-Zarooni's Moulton Paddocks stables failed tests for painkillers in April last year.

"We did talk to him and say to him he needed to keep his records maintained in a much more efficient manner," Crisford said. "We said to him, 'You have to manage your stables better.'

"I had lengthy conversations with him about that but I'm afraid he's betrayed the trust we put in him and he's let everybody down extremely badly, not only Godolphin but the British public, too."

Al-Zarooni has admitted to administering 15 horses with anabolic steroids, with his defence being that he didn't know he was in breach of the rules because the horses weren't racing at the time.

Crisford, who employed al-Zarooni as one of the two British-based trainers of Godolphin owner Sheik Mohammed bin Rashid al Maktoum, said that excuse was "absolutely amazing" from someone who was worked in England since 2010.

"But then, on the other hand, he knew the British Horseracing Authority were coming (to the stables) to do selective testing," Crisford said.

"He was aware they were coming - why on earth would he administer 15 (horses) anabolic steroids in full knowledge that the BHA were doing selective testing?

"We haven't had an answer from him to that."

The stables formerly run by Al-Zarooni have been locked down temporarily by Sheik Mohammed and BHA officials are set to undertake rigorous testing of all the inmates to ensure there are no more doped horses.

It is likely that Saeed Bin Suroor, Sheik Mohammed's other British-based trainer, will take over the running of al-Zarooni's horses.

AP gjw