The Queen's interest in the Turf can seldom have been keener than during a vintage meeting at her home racecourse last week.

Throughout Royal Ascot, however, a small dark cloud lurked on her horizon and last night it seemed to have condensed ominously.

Nicky Henderson, one of the most successful and respected jumps trainers in the land, was mortified last month when it emerged that one of the horses he trains for the Queen — a mare named Moonlit Path — had tested positive to tranexamic acid after finishing sixth on her debut at Huntingdon in February. The substance apparently traces to a treatment against ‘bleeding,’ or the breaking of blood vessels, a common frailty in thoroughbreds. The test had been matched by counteranalysis in France.

Yesterday the British Horseracing Authority's disciplinary committee found Henderson in breach of Rule 200, in that he was complicit in the administration of a prohibited substance either with the intention of affecting her performance, or in the knowledge that her performance could be affected.

The panel prolonged Henderson's discomfort in excruciating fashion, by declining to set a penalty for the time being. Instead they will be submitting the reasons for their verdict and invite any pleas in mitigation before deciding upon a punishment.

Henderson is entitled to be alarmed, because the available penalties range from a heavy fine to disqualification. Up until now, no doubt, Henderson will have considered a crimson blush ample punishment, but disqualification can be for any period up to five years and as a cornerstone of the National Hunt scene for so many years, he will not have slept well last night.

The Seven Barrows trainer left the hearing, which had lasted eight hours, positive test was disclosed, however, he had issued a statement that seemed to emphasise no sinister intention could have been possible.

"The substance concerned was administered by my vet entirely in the interests of the horse's welfare, which is paramount," he said.

"There was no intention to enhance performance and it is worth pointing out that we won the race in question with the odds-on Ravello Bay. We have co-operated fully with the BHA throughout their investigation."

Despite the success of Art Connoisseur in a rather peculiar race for the Golden Jubilee Stakes on Saturday, Royal Ascot certainly placed the indigenous understanding of "velocity" in chastening context.

It was not just the way Scenic Blast reiterated the gusto of overseas sprinters over the bare five furlongs, but the alarming pace and precocity exhibited by the two juvenile winners produced over the same trip, like rabbits out of a Californian hat, by Wesley Ward.

Even so, Brian Meehan is taking a positive view of his options for Radiohead, who somehow salvaged the Norfolk Stakes after being all but brought to his knees as he was produced to challenge. Perhaps he was spooked into that turn of foot, because he certainly looks a flighty type, but his trainer is now tempted to tap into that energy with a crack at the older sprinters in the Nunthorpe Stakes in August.

In recent years Kingsgate Native and Lyric Fantasy have both made the most of the juvenile weight concession at York.

"I still find it hard to believe that Radiohead managed to win, after taking such a hefty bump sp close to the finish," Meehan said.

"Luckily, he seems none the worse and appears to have taken the race very well."

Canford Cliffs, author of the most visually striking performance all last week, will be given a break before bidding to confirm his Group One substance in France. Richard Hannon confirmed yesterday that the runaway Coventry Stakes winner would be aimed at the Prix Morny at Deauville on August 23.