Michael Jackson had "lethal level" of powerful drugs in his body when he died, according to an official report.

According to a previously sealed search warrant that was made public overnight (August 24), a coroner has concluded the singer's death was a homicide after extremely high levels of the anaesthetic Propofol were found in his system.

Under American law homicide also includes manslaughter, and BBC News reports that investigators are now determining whether there is a charge to answer. 

Police have searched the offices of Jackson's personal doctor, Conrad Murray, who has denied any wrongdoing. 

Although the Los Angeles coroner or police have not released any of their findings officially, the information emerged in Texas after search warrant was issued to search offices Murray has in Houston. 

According the papers the Los Angeles Chief Coroner "had reviewed the preliminary toxicology results and his preliminary assessment of Jackson's cause of death was due to lethal levels of Propofol". 

Earlier this month Murray posted up a short YouTube clip in which he declared: "I told the truth and I have faith the truth will prevail."