The source also said that Murray allegedly gave Jackson an anesthetic propofol before he died.
While, the doctor's lawyers had no comment on the report but in the past they claimed that Murray never prescribed or administered anything that could have killed the pop star.
According to court documents, Texas authorities searched Murray's Houston medical office and storage unit, searching for 'evidence of the offense of manslaughter'.
Tammy Kidd, a spokeswoman at Chernoff's office said, "The search was absolutely a surprise to us, because we've had open lines of communication this whole time."
He also said that the Los Angeles County coroner's office continues to investigate the cause of Jackson's death on Jun 25. It is waiting for toxicology lab results, but a final autospsy is expected in this week.