Michael Jackson's doctor kept mum about propofol at hospital

Two hospital physicians testified on Thursday that Michael Jackson's doctor never admitted to giving him the powerful anesthetic propofol after the singer arrived at their emergency room in cardiac arrest.

The UCLA Medical Center doctors' testimony came on the third day of a preliminary hearing to determine if Dr Conrad Murray should stand trial for involuntary manslaughter in Jackson's death because he was negligent in his care.

Prosecutors have accused Murray of giving Jackson too much propofol at the 'Thriller' singer's Los Angeles mansion to help him sleep, leading to his June 25, 2009 death. And they say Murray tried to cover up his actions after he discovered Jackson had stopped breathing.

Dr Richelle Cooper, the emergency room physician who pronounced Jackson dead at the hospital, and her colleague Dr Thao Nguyen both testified that Murray never mentioned propofol when they asked what drugs the singer had received.

Propofol is an anesthetic typically used in a hospital setting such as surgery, but Jackson was asking for it to be given to him at home as a sleep aid.

"We will often use propofol for some kind of procedure -- to fix a broken bone or a dislocated joint." Cooper said, but added "I've never seen it used in a home setting."

The hospital doctors said Murray did admit giving Jackson the sedative lorazepam, but Nguyen said Murray could not say how much time passed from the singer taking the drug until he stopped breathing.

"He did not have a watch and he did not have any concept of time," Nguyen said, adding that those are the exact words Murray himself used when speaking to her that day.

Prosecutors also offered a timeline leading to Jackson's death in an attempt to show that before Murray realised the 50 year-old singer had stopped breathing in his bedroom, he was busy making phone calls instead of monitoring his patient.

Deputy district attorney David Walgren told the judge earlier this week that Murray has admitted to giving Jackson propofol between 10.40am and 11am that day.

Phone company officials and a Los Angeles police detective testified that Murray, using his two cell phones, was on a series of calls after that time, ending at around 11.51am.

Around noon, Murray discovered Jackson was not breathing, according to prosecutors. The doctor has pleaded not guilty to involuntary manslaughter. His preliminary hearing, which began on Tuesday, is expected to last two weeks.