Jockey Frankie Dettori said he was "very ashamed and embarrassed" after being banned for six months after testing positive for cocaine.
In an exclusive interview with Channel 4 News just days away from his return to riding, Dettori confirmed for the first time that he had taken cocaine.
The rider was suspended for six months by French racing authority France Galop after returning a positive test following a routine examination at Longchamp on 16 September last year.
Dettori was subsequently banned in December, but is poised to return to action at Leicester on Monday evening.
In an interview with Clare Balding, to be broadcast on Channel 4 News at 7pm on Thursday, he takes full responsibility for "a moment of weakness".
He said: "I'm very ashamed and embarrassed, and paid a very big price for it, you know. I spent six months not doing the thing that I love, racing.
"Things were going bad, I was depressed and I guess a moment of weakness and I fell for it and I've only got myself to blame. I can't blame anybody else.
"The embarrassment of when it come out, I had to hide in my house for a week. The paparazzi outside.
"The embarrassment of telling the children, you know. You know they still go to school, they might get bullied and so it was a very, very difficult time."
Dettori also tells Balding why he took the drug, the impact on his personal life, and his future career in racing.
The 42-year-old will also address the steroid scandal at yard of Mahmood Al Zarooni, trainer for his former retained stables Godolphin.
While the interview will be shown tomorrow evening, further footage will be available on Channel 4 News online and from Friday, 17 May on Channel 4 Racing.