WASHINGTON, June 26 (RIA Novosti) - The cause of the death of U.S. pop star Michael Jackson may not be known for weeks, investigators said on Friday.

Los Angeles County Coroner Jerry McKibben said the autopsy would be held later on Friday, but results were unlikely to be final until toxicology tests had been completed, which could take several days or weeks.

McKibben, however, said if the cause of death could be determined by autopsy, the results would be announced.

Jackson, whose stunning career spanned five decades, died in Los Angeles on Thursday at the age of 50.

"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.