Lawyers representing Michael Jackson's doctor Conrad Murray have won an extra court hearing to ask for medical items found in the late star's bedroom to undergo vigorous testing as they battle to clear the physician's name.

The medic has pleaded not guilty to a charge of involuntary manslaughter following the singer's tragic death last year and he is expected to go on trial in 2011.

A coroner ruled Jackson died of cardiac arrest brought on by an overdose of anaesthetic Propofol, and Murray's lawyers want two syringes and an IV bag, found at the star's Californian home, to be tested to determine the amount of drugs they contained.

Defence attorney, J. Michael Flanagan, argued in legal papers filed in a California court last Friday, "An essential fact in this case is not only how much Propofol was in Michael Jackson's body but how it was put into his body."

A judge has now granted the request for an extra hearing to decide whether the items should be sent back to the laboratory, according to the Associated Press.

Superior Court Judge Michael Pastor will hear the arguments on Dec. 29, just days before Murray is due in court for a preliminary hearing on Jan. 4 to determine whether he will stand trial.