The ongoing investigation into MICHAEL JACKSON’s death is taking longer than expected due to a lack of police working on the case, according to U.K. reports.

Los Angeles police are working alongside the Drug Enforcement Administration (DEA) to try to discover whether the star’s death on June 25 (09) was a homicide due to the amount of prescription drugs he was given.

So far, the probe has concentrated on Jackson’s personal physician Dr. Conrad Murray, who, according to an affidavit that was unsealed on Monday (24Aug09), administered a cocktail of potent narcotics to Jackson on the day of his death to help him sleep.

Two pharmacies have been raided, and subpoenas served on Jackson’s dermatologist Dr. Arnold Klein to obtain the singer’s medical records.

But two main witnesses have reportedly not yet been interviewed – security personnel Alberto Alvarez, who called 911 when Jackson was found unconscious, and the Thriller star’s chief of staff, Michael Amir.

According to Britain’s The Sun newspaper, the LAPD is struggling with the workload involved – because only three detectives have been assigned to the case.

Carl Douglas, a lawyer who represents Alvarez and Amir, even claims he has arranged meetings for his clients with the LAPD on two occasions, with both interviews falling through.

He tells the publication, “We arranged two occasions for investigators to meet my clients.

“The first meeting was rescheduled. The second I had to call them to enquire about the detectives’ absence.”

Los Angeles Coroner is expected to announce more details of Jackson’s death on Friday (28Aug08).