George Michael had a cocktail of drugs in his system when he was found slumped at the wheel of his car, a court heard yesterday.

They included cannabis and the "date rape" drug GHB, also known as liquid Ecstasy.

Tests on blood taken from the pop singer, 43, showed they were in a potentially lethal combination with sleeping pills and anti-depressants.

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George Michael: The singer will be sentenced after admitting to driving while unfit due to drugs

Michael was arrested for driving while under the influence of drugs after he was found semiconscious in his Mercedes at traffic-lights in Cricklewood, North London, in October.

The singer, real name Georgios Panayiotou, initially denied driving while unfit through drugs but changed his plea to guilty at a hearing earlier this month.

The case was then adjourned while the blood tests were concluded to see if the drugs in his system were prescribed or illegal.

When the hearing resumed yesterday, Brent magistrates were told Michael had taken a "high dose" of the sleeping tablets Zolpidem, a therapeutic dose of anti-depressant Efexor and the class C drug GHB.

Dazed: The singer was found slumped at the wheel of his car in Cricklewood in October last year

The clear hallucinogenic liquid is popular on the gay clubbing scene and sells for about £45 a bottle. But it can be fatal when mixed with alcohol and other depressant drugs.

Experts say a single dose of the illegal drug can impair the ability to drive by the same amount as six alcoholic drinks. High doses can cause sleepiness and loss of consciousness.

Cannabis was found in the singer's blood, but experts said it was not the cause of his intoxication and it was impossible to tell when he had taken it.

Michael, who was not present at the hearing, says he had not used cannabis since the evening before his arrest.

Michael Grieve, defending, said the presence of GHB may have been caused by Michael taking a legally prescribed drug, GLB, which has the same effect on the body.

He said: "It is the defendant's case that his condition was caused by taking prescription drugs.

"There is a strong body of opinion that Zolpidem - a prescription drug - was the most likely explanation of his condition.

"The alternative explanation that the substance known as GHB was the main cause would have been disputed.

"But in any event it is common ground that GHB can be present in the blood without any illegal substances being taken."

Driving while unfit through drugs carries a maximum jail term of six months. Michael is due to be sentenced on June 8, the day before performing at Wembley Stadium.