The Galway Hurdle, one of the feature events of this week’s Galway Festival, was embroiled in controversy on Thursday after Petrol Head, who had been backed from 16-1 to 5-1 clear favourite for the €270,000 (£228,000) handicap, was scratched on the orders of the Irish Horseracing Regulatory Board (IHRB) due to a failed dope test after a win at Bellewstown last month.

Petrol Head was due to run for trainer Katy Brown on Thursday, but was previously owned and trained by Ronan McNally and was among the horses involved in a disciplinary case in 2023 which saw McNally banned from racing for 12 years for “causing serious damage to the interests of horse racing in Ireland”.

The IHRB said in a statement on Thursday that it had received confirmation “at 11am … of the presence of a prohibited substance in the sample [taken from Petrol Head] at Bellewstown [on 6 July]. As a result of this confirmation and following the IHRB investigation into the matter, the directors of the IHRB have withdrawn Petrol Head from the Galway Hurdle under the provisions of the Rules of Racing.”

Paddy Power reported significant interest in Petrol Head throughout the morning, despite having been just 8-1 overnight. “We saw plenty of cash for the horse and he was the best backed animal in the race prior to the withdrawal,” a spokesperson said.

McNally received one of the most significant bans ever handed out in Irish racing in January 2023 after he was found to have achieved “a pattern of improvement in form of horses at a level previously unfamiliar to experienced and long-serving handicapping officials”.

He was also found to have conspired with fellow trainer David Dunne to conceal his ownership of three horses – including Petrol Head – in Dunne’s yard, and to have passed on inside information for betting purposes.

Petrol Head now runs in the colours of the Orchard Garden Syndicate, and Brown later told the Racing Post that there is “no connection” between the horse and McNally. Brown also said she had not administered any prohibited substance to Petrol Head before his run at Bellewstown.

In Petrol Head’s absence, Joseph O’Brien’s Nurburgring, at 13-2, was an impressive winner of the day’s feature race under JJ Slevin.

At Goodwood, a flawless front-running ride by Ryan Moore helped Opera Singer, last year’s champion juvenile filly, to secure her first win as a three-year-old in the Group One Nassau Stakes. Moore soon had Opera Singer, the 9-4 second-favourite, settled and travelling easily on the lead, and clearly had his pursuers in trouble after kicking for home two out.

Thursday’s 10-furlong race was Opera Singer’s first start beyond a mile and she is now among the favourites for the 12-furlong Prix de l’Arc de Triomphe at Longchamp in October.

“When Ryan got off her after the Boussac [at Longchamp last October], he said, this filly will come back and win the Arc,” Aidan O’Brien, the filly’s trainer, said. “There’s every chance she’s going to get a mile-and-a-half and she’s very classy. She’s by Justify and they don’t stop, they just keep going.”

The British Horseracing Authority confirmed in a statement on Thursday that Charlton “has been granted a temporary licence to train from the yard in Sherborne, Dorset at which Mr Syd Hosie has trained most recently. Mr Charlton’s licence has conditions attached, which will not be made public and horses declared earlier this week from the yard will be permitted to take up their engagements.”

TV preview

The official Group One action at Glorious Goodwood is over for another year but Friday’s feature, the Group Two King George Stakes, promises to be as classy and competitive as any race at the meeting.

There are four previous Group One winners in the field – Big Evs, Live In The Dream, Moss Tucker and Asfoora, the Australian-trained winner of the King Charles III Stakes at Royal Ascot – while Believing has looked like a Group One win waiting to happen several times already this year.

She is not the only potentially top-class sprinter in the field, however, as Jack Channon’s Desperate Hero (3.35) is another fascinating contender. He produced the outstanding sprint handicap performance of the season at Hamilton in June, recording a Group-class time figure in the process, and looks tailor-made for Friday’s test of pure speed on one of the fastest five-furlong tracks on the planet.

Desperate Hero dipped well below his Hamilton form when stepping up to Group company at Sandown last time, but that was on soft ground and a lightning-fast surface is key to his chance. Significant rain at Goodwood would significantly dampen enthusiasm, but if the possible thunderstorms avoid the track, he will be a big runner at around 16-1.

Goodwood 1.50 A unique annual test over two-and-a-half miles and the last two winners – Temporize and Master Milliner return for another crack. Marginal preference is Emma Lavelle’s gelding, who is lightly raced since his win in 2022 and returns on a 3lb lower mark.

Goodwood 2.25 Al Musmak took a significant step forward to win at Newmarket last month and has room for further progress with only seven starts in the book

Goodwood 3.00 David O’Meara has won two of the last four runnings of the Golden Mile and has a strong hand again here, including Blue For You, Orbaan – the 2022 winner – and Darkness. The latter, a close fourth from a high draw and 3lb higher mark last year, could be the value at around 14-1 from stall eight.