Michael Jackson could have been murdered — police investigating the superstar’s death have launched a murder investigation.

The music legend died June 25 after suffering an apparent cardiac arrest at his home in Los Angeles. It is widely believed that an overdose of painkillers caused Jacko’s untimely demise.

Detectives are waiting for toxicology tests and have revealed they seized a number of items from the star’s home at the time of his death.

They have also subpoenaed all Jacko’s medical records.

Officers say that because the star died after allegedly taking a cocktail of drugs somebody must face trial over his death.

If it was ruled that the 50-year-old was murdered, anyone found guilty would face the death sentence, possibly by lethal injection.

Los Angeles police chief William Bratton described his force’s investigation as “comprehensive and far-reaching”.

Bratton insisted his detectives would wait for the coroner’s report on what caused Jacko’s death before ruling out any possibilities.

He said the report depended on the results of time-consuming toxicology tests.

“Based on those we’ll have an idea of what we’re dealing with,” Bratton said.

“Are we dealing with homicide? Are we dealing with an accidental overdose? What are we dealing with?

“At the time of the death with search warrants, we were able to seize a number of items from the residence where the death had occurred and those will assist in the investigation.

“The next move really is his. We’re not marking time waiting for his report.”

It has also been claimed that two medics — Dr Arnold Klein and Dr Conrad Murray, who was with Jackson when he died — have not turned over all the medical records they have been asked for.

Earlier this week, it was claimed that Michael’s body was riddled with needle marks when he died.

The multiple track marks and several collapsed veins — discovered after Jackson’s body was examined June 25 — could indicate he was using a powerful sedative, Diprivan, at the time of his death, CNN and ABC News reported.

On Wednesday’s Larry King Live, Jackson’s dermatologist admitted the singer had used the sedative, administered with an IV.

“I knew at one point that he was using Diprivan when he was on tour in Germany. And so he was using it, with an anesthesiologist, to go to sleep at night,” Arnold Klein said. “And I told him he was absolutely insane. I said you have to understand that this drug, you can’t repeatedly take. Because what happens with narcotics, no matter what you do, you build a tolerance to them.”

Diprivan is usually used to induce unconsciousness in hospital patients before they undergo major surgery.