An official with the Los Angeles County Coroner's office says toxicology reports that may determine the cause of Michael Jackson's death could be completed soon.

Assistant Chief Coroner Ed Winter said that some of the results from tests to determine what substances Jackson may have had in his body when he died are in.

The outstanding toxicology results are expected at the end of this week or early next week. When all the tests are done, the results will be released the next day.

For now, the music icon's cause of death is officially listed as unknown.

Depending on what drugs Jackson took and who gave them to him, the LAPD has not ruled out classifying the singer's death a homicide. To that effect, Michael's sister La Toya has suggested that essentially, Jackson was murdered.

Michael Jackson died suddenly of cardiac arrest June 25.

Authorities are investigating claims the star consumed large amounts of prescription drugs. The powerful anesthesia Diprivan (the brand name of Propofol), normally only administered in hospitals, was among items found in his home.

In addition to the toxicology tests, the LAPD and the coroner's office has subpoenaed medical records from doctors who have treated Jackson in recent years.

Recent reports have suggested that investigators' focus is zeroing in on Dr. Conrad Murray, who was Jackson's personal physician at the time of his death.