The 37-year-old was given an eight-year ban from the sport last week, after admitting to administering anabolic steroids to 15 horses in his care.
Anabolic steroids are banned by the BHA, but are permitted elsewhere away from competition days, including Dubai where Godolphin have training facilities.
And Al Zarooni had his claims of making an innocent mistake dismissed by the BHA, who also ruled that he had personally brought the steroids into the country from the Gulf.
“Al Zarooni’s assertion at the hearing that he did not know that such administration was not permitted in the UK was simply not truthful,” the findings read.
“He had access to expert veterinary advice but deliberately ignored this resource and chose to covertly administer to horses in training anabolic steroids which he had brought back into the UK in his luggage from Dubai.”