The doctor accused of causing Michael Jackson's untimely death has pleaded not guilty to charges of involuntary manslaughter, insisting "Your Honour, I am an innocent man."

Conrad Murray is said to have administered the king of pop with propofol - a powerful surgical anaesthetic intended for clinical use only - combined with other drugs to tackle the singer's debilitating insomnia.

This combination proved lethal, resulting in the 50-year-old's death on June 25, 2009.

Michael's mother Katherine, along with brothers Jermaine and Randy and sister Rebbie were all present in the Los Angeles court to witness the defendant's plea.

A trial date has been set for March 28 and a pre-trial hearing for February 7.

If convicted, the doctor could face up to four years in prison.

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