The doctor, who prosecutors say caused the death of pop star Michael Jackson, was released from jail after posting $75, 000 in bail, only a few hours after surrendering to authorities on a manslaughter charge.

A Sheriff's Department spokesman said doctor Conrad Murray was released Monday afternoon local time.

Earlier in the day, Murray appeared in court in a grey suit as Jackson's father Joe, mother Katherine, and siblings LaToya, Jermaine, Tito, Jackie and Randy watched from courtroom seats behind prosecutors.

Neither Murray nor the Jacksons showed much emotion as Murray entered his plea through his attorney Ed Chernoff.

However, after the hearing Joe Jackson, Michael's father, expressed his outrage at the proceedings and the manslaughter charge levelled at Murray.

"This was not justice.....because my son was murdered" he told reporters.

Earlier, several people heckled Murray as he walked past a crowd of hundreds of reporters and Jackson fans on his way to the courthouse adjacent to Los Angeles International Airport.

Murray, 56, a Houston cardiologist who was with Jackson when he died on June 25, entered his plea just hours after he was charged.

Superior Court Judge Keith L. Schwartz set bail at 75-thousand US dollars, three times more than the amount most people face after being charged with involuntary manslaughter.

Prosecutors had been seeking 300-thousand US dollar bail for Murray, who was taken into custody by deputies but not handcuffed in public.

The judge told Murray he could travel throughout the United States after posting bail but must surrender his passport and not leave the country.

It appeared authorities were taking extra steps to ensure the arraignment did not become a media circus.
Lines were formed to gain admission to the courtroom, and the Jackson family were escorted in separately and seated before anyone else arrived.

Despite the precautions, the upcoming proceedings promise to be the focus of widespread attention. Jackson, 50, hired Murray in May to be his personal physician as he prepared for a strenuous series of comeback performances.

Officials said the singer died in Los Angeles after Murray administered the powerful general anaesthetic propofol and two other sedatives to get the chronic insomniac to sleep.

Murray is accused of the single felony count in a five-page complaint that said he "did unlawfully, and without malice, kill Michael Joseph Jackson" by acting "without due caution and circumspection."

Known as "milk of amnesia," propofol is only supposed to be administered by an anaesthesia professional in a medical setting because it depresses breathing and heart rate while lowering blood pressure.

Murray has said he did nothing that should have caused Jackson to die. If convicted, the doctor could face up to four years in prison.

Speaking after proceeding Murray's lawyer, Ed Chernoff, said the doctor planned to return to his medical practices in Houston and Las Vegas while he awaits trial.

"He's going to make it and he'll be back home with his family and back to his medical practice this week" Chernoff said.

However, state officials said they plan to ask that the court suspend his medical license while he is free on bail.