DUBAI/LONDON — Godolphin is to close the Newmarket stable of trainer Mahmood Al-Zarooni while dope tests are carried out on all racehorses in his care after 11 tested positive for steroids, Dubai's ruler Sheikh Mohammed said Wednesday. “There can be no excuse for any deliberate violation,” Sheikh Mohammed said in a statement sent to Reuters. “I have been involved in British horse racing for 30 years and have deep respect for its traditions and rules. I built my country based on the same solid principles,” said Sheikh Mohammed, adding he was appalled and angered about the case. Zarooni, who has admitted using banned steroids to dope racehorses, will face a disciplinary panel in London Thursday, the British Horseracing Authority said earlier Wednesday. Eleven horses based at Newmarket in southern England tested positive for steroids, including stanozolol — the substance used by disgraced Olympic sprinter Ben Johnson at the 1988 Seoul Olympics. Announcing the date for the disciplinary hearing, the BHA said Al-Zarooni had also admitted administering prohibited substances to four other horses under his care, in addition to the 11 that were tested positive. “Godolphin is fully cooperating with the British Horseracing Authority to get to the bottom of this matter and take any appropriate disciplinary action,” Sheikh Mohammed said. “I have ordered the Godolphin management to undertake an immediate review of our internal procedures and controls to ensure to prevent any reoccurence of this type of activity in any stables of mine,” he said. On Tuesday Al-Zarooni said he regretted what he described as “a catastrophic error”. Al-Zarooni said Monday that the horses involved weren't racing at the time so he “did not realize that what I was doing was in breach of the rules of racing.” Samples were taken from 45 horses at Godolphin's Moulton Paddocks Stables on April 9. “We will be locking down the Moulton Paddocks stables with immediate effect, and I have instructed that I want a full round of blood samples, and dope testing done on every single horse on that premises,” Sheikh Mohammed said. “I can assure the racing public that no horse will run from that yard this season until I have been absolutely assured by my team that the entire yard is completely clean,” he said. One of the horses to test positive was Certify. The filly will not now be allowed to take part in the 1,000 Guineas at Newmarket next month. Unbeaten in four career outings, Certify was one of seven horses to test positive for ethylestranol. Gold Cup runner-up Opinion Poll was one of four to test positive for stanozolol. “I have worked hard to ensure that Godolphin deserves its reputation for integrity and sportsmanship, and I have reiterated to all Godolphin employees that I will not tolerate this type of behavior,” Sheikh Mohammed said. Founded in 1992, the Godolphin stable has won more than 2,000 races worldwide with winners in 14 countries. Sheikh Mohammed's brainchild was born out of his frustration at constantly finding his British trainers reluctant to abandon the fight for classic glory at home to travel abroad. His passion for horses helped transform Dubai into a world power in flat racing; its annual World Cup in March is the world's richest race with a $10 million purse. Godolphin's 2012 racing season was its most successful on record, earning $25.9 million in prize money, its website shows. British bookmakers said they would refund bets that have been placed on horses trained by Al-Zarooni.— Reuters