In a frank, exclusive interview about his own drug misdemeanours and future in horse racing, jockey Frankie Dettori says trainer Mahmood al-Zarooni - banned for doping horses - "ruined" his career.

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Top jockey Frankie Dettori has admitted for the first time that he took cocaine last year, describing himself as "very ashamed and embarrassed" about the drug use which led to his six-month ban in December.

In an exclusive interview with Clare Balding for Channel 4 News as he prepares to return to horse racing, Dettori described it as a "moment of weakness" which he has "paid a very big price for".

But while Dettori has had his own demons to fight in the last six months, he also has a unique perspective on a scandal which rocked horse-racing just weeks ago.

His former stables, Godolphin, was engulfed in a doping scandal at the end of April which has seen top trainer Mahmood al-Zarooni banned for eight years by the British Horseracing Association. Trainer al-Zarooni plans to appeal the length of the ban but has already admitted the "catastrophic error" of doping 15 racehorses.

Dettori said he was shocked by the story implicating his former stables, which is owned by the ruler of Dubai, Sheikh Mohammed.

"I was shocked when the amount of horses was found positive...but I wouldn't even know the difference between a horse on steroids, and a horse not on steroids," he said.

But Dettori has a wider argument with al-Zarooni, and blames him in part for the unravelling of his own relationship with Godolphin, who he worked with for 18 years before splitting acrimoniously last year. Dettori says his "depressed" frame of mind after the split was one of the key factors in his drug-taking.

The relationship deteriorated so much that Sheikh Mohammed, who Dettori previously considered a father-figure, has twice not met with the jockey despite Dettori flying to Dubai.

Split from Godolphin

The jockey split from Godolphin when he grew unhappy about other top riders being brought in, meaning he was no longer the first choice to ride the best horses. His provocative choice to ride for another stables, rival Coolmore, effectively marked the end of the relationship.

"My first seventeen years of my riding career [at] Godolphin, I was always the number one pick. All of a sudden I saw myself being the fourth in the biggest race in the world," he said.

"You start getting depressed. I wasn't sleeping at night. I was arguing with my wife… My head was wrecked, absolutely wrecked. I couldn't take it anymore.

"Another six months there and I definitely would have been in the Priory."

Dettori believes it was al-Zarooni who wanted him out of Godolphin.

"I had some great success with him, that's why I couldn't figure why he wanted me out," he said. But it seems his opinions of the trainer have hardened since, particularly regarding the doping scandal.

"It has [Godolphin] been ruined by one person. He has ruined my career to start, and now he has ruined Godolphin," he said.

For more from our exclusive interview with Frankie Dettori and his cocaine use, as well as his feeling that he has become like Lance Armstrong, click here.

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