A confidential document from the Santa Barbara County Sheriff’s Department states that dead King of Pop Michael Jackson took more than 10 Xanax pills a night and used his staff to purchase them.

The document, containing confidential interviews conducted with two of Jackson’s former security guards, was compiled as prosecutors prepared for Jackson’s child molestation trial in 2005 and also claims the entertainer personally traveled to doctor’s offices in other states to obtain the powerful drug.

Though Jackson was acquitted after the 14-week trial, the information about the sleeping pills, and the lengths Jackson went to get them, adds to a growing mountain of claims tying the singer to drugs in recent days.

Los Angeles Police Chief William Bratton said detectives have spoken to a number of doctors who treated Jackson over the years, and are looking into the singer’s prescription drug history.

Doctors who did not cooperate with investigators were issued subpoenas and if necessary more will be issued, a source close to the investigation said.

Jackson died on June 25 and authorities are waiting toxicology reports from the coroner’s office to determine the exact cause of death.

The speculation that prescription drugs, particularly sedatives, could have played a role in Jackson’s death keeps coming up with each new nugget of information – and there have been many.

One medical expert, speaking on condition of anonymity, described the amount of Xanax Jackson is reported to have taken as “extremely high”.

In addiction cases, people develop a tolerance to drugs and have to take more and more.

“No matter how you cut it, this is an extremely high dosage of Xanax. It is a huge red flag, even with the tolerance that I was talking about. This dosage is exceedingly high for any human being.”

The 2004 document details a dark picture of Jackson’s attempts to battle his sleeping disorder.

One security guard said he expressed his concern about Jackson’s use of 10-plus pills a night to another staffer. The second staffer replied, “Jackson was doing better because he was down from 30 to 40 Xanax pills a night,” according to the document.

One of the guards said he and three other employees would get prescriptions for Jackson under their names.

The second guard backed up the claim, saying he had picked up medicine for the singer that were in other people’s names.

The document contains the names of five doctors – some in California, some in New York and others in Florida. It was not immediately clear whether police have spoken to them as part of their investigation into Jackson’s death.

After the doctor visits, Jackson would be “out of it and sedated,” one guard said.

According to the sheriff’s office document, the guard who provided the bulk of the information quit his job after Jackson “fell on his face” in a hotel room and hurt himself. The employee told Jackson he was not comfortable getting prescriptions for him and left, he later told investigators.

Along with the police investigation, which is being aided by the state attorney general’s office and the Drug Enforcement Administration, the Los Angeles County coroner’s office has also drawn up a list of Jackson’s doctors and is trying to talk to them to determine what drugs they may have prescribed him.

Among them are Dr. Arnold Klein, Jackson’s dermatologist, and Dr. Conrad Murray, his cardiologist.

Klein said Wednesday that Jackson was addicted to drugs at one point but had kicked the habit.

Murray, who has been interviewed by police, has repeatedly said he will withhold comment until the coroner’s tests are back.

Among others who have indicated that Jackson may have been using dangerous prescription medication are a nutritionist, Cherilyn Lee, who said Jackson pleaded for Diprivan despite being told of its harmful effects.

Sources close to Jackson have reported that the singer traveled with an anesthesiologist who would “take him down” at night and “bring him back up” during a world tour in the mid-90s.

Another source involved with the investigation said police found numerous bottles of prescription drugs in the singer’s $100,000-a-month rented mansion in Holmby Hills.

The Associated Press and the Los Angeles Times, citing unnamed sources, said police found Diprivan.

Diprivan is a powerful sedative that is administered intravenously and is known by its generic name Propofol.