Aidan O'Brien has been referred to the BHA and faces a fine of up to £2,000 after refusing to allow racecourse vets to examine his Dante Stakes winner Cape Blanco after the race.
The unbeaten colt was cut to 4-1 second favourite for the Derby after his three-and-a-quarter length victory from Workforce at York, but rumours soon spread about his soundness after comments on C4.
Stewards' secretary Robert Earnshaw telephoned O'Brien at his Ballydoyle base but said the trainer had refused permission for the colt to be trotted up by the course vet or ensure that his stable representative was interviewed by the stewards.
O'Brien's refusal to co-operate was bizarre as his stable representatives claimed the colt's soreness was short-term, having knocked an ankle he nicked at the weekend.
Cape Blanco's Derby odds drifted to 8-1 at one stage on Betfair and Paddy Power removed him from their lists.
This was poor PR as racing strives to modernise and operate more openly. Cape Blanco's win boosted the claims of stablemate St Nicholas Abbey, the yard's No 1 hope.
Runner-up Workforce could still run at Epsom but third Coordinated Cut looks Royal Ascot bound.
Godolphin's Chabal was tailed off in fourth, increasing chances that Simon De Montfort, recently switched to Britain from Andre Fabre, will be supplemented for the Derby.
The result and the post-race furore made the Dante, usually so reliable, an unsatisfactory trial.
Murtagh was happy with Cape Blanco's effort but he stuck to the line that St Nicholas Abbey, cut to 5-2 favourite, is the main O'Brien hope.
The jockey said: 'Cape Blanco is unbeaten, very genuine and tough. He got a bit outpaced when they quickened but when he got back on an even keel he really went to the line well.
'I'm not 100 per cent certain but I think he will stay. Nothing phases him and he is very straightforward - a typical Galileo in that he always wants to please.
'But you saw St Nicholas Abbey winning the Racing Post Trophy and he was nowhere near as good in the Guineas (when sixth).
Runner-up Workforce, running for only the second time, could still line up at Epsom if Sir Michael Stoute wishes.
Lord Grimthorpe, racing manager to owner Khaled Abdullah, said: 'That was only his second run. He hung a bit entering the straight and the bit went through his mouth.
That does not help but it does not make him three and a quarter lengths better.