Police started investigating Michael Jackson's personal doctor after a detective's suspicions were aroused by chat with his neighbour

LAPD officer Orlando Martinez told a doctor friend that he had found an empty medicine bottle under a table in the singer's room while investigating his sudden death.

And when the neighbour found out it was a bottle of a powerful anaesthetic called propofol he told Martinez something was wrong.

The detective said: “In Michael's room where he was treated a bottle of propofol had fallen on the ground and moved under this moving nightstand. I didn't know what it did.

“My neighbour was a doctor so I asked him about it. He was the one who got it started with 'whoa, what is this doing there, it's only used in surgery to put people under.”

(Image: Zig Zag Productions.) (Image: Getty Images)

New details of the investigation into the superstar's demise are revealed in a documentary which will air on British TV in the run up to the 10th anniversary of his death.

Jackson's physician Murray Conrad was jailed for four years after administering propofol through an IV drip to help Jackson sleep.

He was giving the King of Pop nightly infusions of the drug to enable him to rest for his impending This Is It tour.

But police found he failed to monitor Jackson properly.

Now three detectives involved in the original probe have given insights into the investigation.

They were left furious after prosecutors charged Murray with involuntary manslaughter instead of second degree murder.

Martinez and colleagues Dan Myers and Scott Smith believe prosecutors went with the lesser charge because of past criticism over celebrity cases, including that of OJ Simpon who was acquitted of killing his wife Nicole Brown Simpson in 1994.

Myers tells a documentary makers: “I don't think the office wanted a high profile failure. It was an election year for the DA (district attorney).

“I think it was a, I don't want to say the lazy way out, but the charge was the path of least resistance. We felt the evidence suggested it was second degree.”

(Image: Quest Red)

(Image: LAPD)

Fellow detective Martinez said he thought the “level of negligence was just so clear” the team were sure of a second degree murder charge, which carries a possible life term.

“We don’t charge people, we investigate the case and present it. We were not happy with the choice but we deal with what we can,” he says.

“For us, working the cases, we didn't want to make the same mistakes the department remembers and are in the public memory. There was a lot of pressure to get it right.”

They also tell how Conrad – who put his medical bag in a wardrobe after Jackson's death – dropped himself in hot water during interviews.

Martinez says: He freely admitted that for months he had been using it (propofol) to help Mr Jackson to sleep. I was completely blown away. In my head I was thinking...to drug someone to sleep? Even with their permission I didn’t think it was legal.”

Officer Scott Smith says: 'He assumed we had his bags. Once he realised we didn't he had a deer in the headlights kind of look.”

The policemen also told how they were disappointed Conrad was not put in handcuffs during his arrest after his lawyers struck a deal with the Attorney's Office to hand himself in.

Myers said: “I wanted to see Murray in handcuffs, and I think a lot of people wanted to see him in handcuffs, but in this case the rules were changed.”

Jackson paid the cardiologist around £119,000 a month to help him sleep and wanted to take him on tour with him.

Conrad, in debt from a luxury lifestyle which included a million dollar home, was one of several doctors the star had asked to help him.

He claimed his intention was to wean the singer off the drug but prosecutors argued his negligence included leaving Jackson unmonitored while the anaesthetic was pumped into his vein through an IV drip.

Detective Smith said: “There were other doctor's Michael had reached out to to administer propofol to his liking when he wanted it and was turned down.

(Image: LAPD)

(Image: Orlando Martinez.)

“he was looking for someone who would administer it, as wrong as it was.”

Murray served just two years of his four year sentence due to prison overcrowding and good behaviour.

Jackson has been plagued with accusations of child sex abuse, even in death.

In 1993, thirteen-year-old Jordan Chandler alleged he was molested by the Billie Jean songwriter but dropped his claims when Jackson paid the family a huge settlement.

In 2005 he faced charges for molesting another 13-year-old boy and a jury found him not guilty.

This year two men who knew the star as children, Wade Robson and James Safechuck, said he abused them in a shocking documentary called Leaving Neverland.

Killing Michael Jackson shows next Saturday, June 22, on Quest Red at 10pm