Frankie Dettori, the most celebrated figure in British horse racing, faces lengthy suspension after testing positive for a banned substance

Dettori had four rides at Longchamp on September 16, a day of major trials for the Prix de l'Arc de Triomphe meeting (Getty Images)

Frankie Dettori, the most celebrated figure in British horse racing, faces a lengthy suspension after testing positive for a banned substance when riding in Paris in September.

Failure to establish his innocence at a hearing in France next week would result in a worldwide ban, liable to extend to six months.

Though arguably still the world’s No 1 rider, at 41, Dettori was already at a crossroads in his brilliant career. After 18 years with Godolphin, last month the Italian parted company with Sheikh Mohammed’s elite stable in order to ride as a freelance in 2013. A young French jockey, Mickael Barzalona, had been hired to share his duties at the start of the season, and Dettori was vexed when his inexperienced rival was given immediate parity.

Dettori’s solicitor, Christopher Stewart-Moore, issued a brief statement confirming that he had been summoned to appear before the French authorities. “On behalf of Frankie Dettori I can confirm that, as a consequence of a positive test at Longchamp on September 16, he will be the subject of an inquiry by the Medical Committee of France Galop next week,” he said. “In compliance with, and out of respect for, the regulations of France Galop, he will not be commenting further until the France Galop procedures have been completed.”

Long cherished for the effervescence of his character, Dettori has become one of racing’s elder statesmen since the days of his precocious emergence as a teenager. He is an MBE and family man – he has had five children with his English wife, Catherine – and his one known flirtation with recreational drugs had long been consigned to history. Dettori accepted a police caution in 1993, after being found in possession of a small quantity of cocaine. Reflecting on that episode two years ago, he said: “That wasn’t about losing weight. That was for fun. I was a stupid, cocky, arrogant kid.”

A few years later, he admitted using a variety of diuretics before their prohibition by the racing authorities, telling the BBC: “I took Lasix, pee pills, diuretics, laxatives – all sorts.” There is an anecdotal tradition that jockeys, who tend to eat little in order to keep their weight under control, are prone to distract their appetite in other ways. But frequent, random urine tests have yielded few positive results over the years, albeit a handful of jockeys have been given shorter suspensions for failing random breathalyser tests for alcohol.

Today’s news, even so, evoked poignant memories of the tribulations of another former champion jockey. Kieren Fallon also tested positive in France, on two occasions, during a time of rather more grievous crisis. In 2006, when facing corruption charges, he was banned for six months – and then for another 18 months, when failing another test the following year. News of that second offence broke immediately after Fallon had cleared his name, in a collapsed race-fixing trial at the Old Bailey.

If not to the same lurid extent, Dettori in turn finds himself in danger of hastening from frying pan to fire. For he is understood to have been profoundly hurt by the fast-tracking of Barzalona, and was desperate to reiterate his undiminished powers next year. Depending when any ban might come into effect, he could expect to be back in action before Royal Ascot in June – but that would represent the coldest of comforts, when he already feels he has so much to prove.

Dettori was scheduled to ride on the last day of the British Flat season, at Doncaster last Saturday, but ultimately did not do so. He is now understood to be in Dubai. Some, inevitably, will ask whether he may contemplate retirement, but the man who famously rode all seven winners on a top-class racecard at Ascot in 1996 would never choose to end his career in humiliation. Whatever the inquiry discloses, Dettori would seem certain to win pardon from the professional community of trainers, owners and breeders upon whom he would depend for rides on his return.