Murphy, who was crowned Britain’s champion Flat jockey for the second successive year last month, failed a test at Chantilly on July 19 – having ridden The Lir Jet, owned by his bosses, Qatar Racing.
Having always strenuously denied he had taken any drugs, Murphy requested a B sample – and upon receiving the results, France Galop held a hearing on November 25, where the rider’s defence of environmental contamination from a sexual encounter and scientific hair test evidence was accepted.
Murphy’s three-month suspension took into account his defence, and will run from December 11 until March 11.
Speaking to BBC Sport, Murphy admitted he had witnessed cocaine being used the night before travelling to France.
Murphy said: “I became aware of a situation where cocaine was present in my environment and I saw it there and didn’t remove myself from that situation immediately.
“When you sign for your jockey’s licence every year you have got to abide by the rules.
“That was my error, and I very much have no self-pity. I made a mistake and I’ve got to live with the consequences.
“I got up the next morning and went to France and thought nothing of it. But I should have thought much more of it, and that was the block I have stumbled on.”
Murphy plans to use his time out of the saddle to reflect on what has happened.
He added: “I’ve never taken cocaine. I made a massive error and I’m missing out on plenty. I should be in Japan this time of the year, I love riding there. I’m going to miss the big races in Saudi Arabia and Super Saturday in Dubai.
“But I need to put things right and I need to use my time over the next three months to do the right thing and take the right step.
“This is going to go down on my CV – nobody is going to forget about this overnight.
“I’ve projected myself as a good ambassador for the sport, but clearly a good ambassador for the sport doesn’t fail a drug test, no matter how minimal that quantity is.”
