While there's speculation and reports that prescription drugs may have played a part in Michael Jackson's death, an autopsy is set to be performed on the late King of Pop on Friday to determine what caused his sudden death.

Though the autopsy will be completed on Friday, generally results from such a procedure take several days or even weeks depending upon the situation. Los Angeles County Coroner Investigator Jerry McKibben has said that should they be able to determine a cause of death from the autopsy, the results will be announced shortly after.

Jackson died on Thursday at at UCLA Medical Center after suffering a cardiac arrest, according to his brother Jermaine. Paramedics rushed to the scene to try to resuscitate Jackson for nearly an hour.

"It is believed he suffered cardiac arrest in his home. However, the cause of his death is unknown until results of the autopsy are known," his brother Jermaine said.

Cardiac arrest is an abnormal heart rhythm that stops the heart from pumping blood to the body. It can occur after a heart attack or be caused by other heart problems.

There have been several reports claiming that prescription drugs may have played a role in the cardiac arrest and death of Jackson, though no doctors or officials have commented on those claims.