Search warrant records released Friday show that Dr. Conrad Murray bought the sedative propofol from Applied Pharmacy Services on May 12, according to receipts found in his Las Vegas medical office.
The Los Angeles County coroner blamed propofol in ruling that the 50-year-old pop music icon's June 25 death was a homicide. The coroner also cited the sedative lorazepam.
Murray, 56, is the focus of a Los Angeles police homicide investigation, but has not been charged with a crime.
The cardiologist, who is licensed in Nevada, California and Texas, told police he used propofol along with other sedatives to help Jackson sleep.
Propofol is usually used in medical settings by anesthesia professionals to render patients unconscious for surgery. Officials say it is not meant for use as a sleep agent. However, the milky liquid drug is not regulated by state and federal authorities as a controlled substance.
Drug Enforcement Administration spokeswoman Sarah Pullen in Los Angeles said a doctor who is licensed in two states can buy propofol in one state and administer it in the other.
Records show he obtained the propofol about the same time he was hired in May to accompany Jackson on a world tour. He told police he administered 50 milligrams of the drug intravenously per night to help Jackson sleep, but was trying to use less.
In the warrant documents, investigators said Murray told them he gave propofol to Jackson in the hours before he died in a rented Los Angeles mansion.
Through a spokeswoman, Murray maintains that he didn't prescribe or administer anything to Jackson that should have killed him.
Murray's attorney, Edward Chernoff, issued a statement Friday saying he found no surprises in the newly released affidavit.
"The fact that Dr. Murray ordered five bottles of propofol is consistent with what he told investigators," Chernoff said.
The affidavit showed that authorities tracing the manufacturing lot numbers of propofol bottles found in Murray's medical bag and on Jackson's bedside table learned that Murray bought five, 100-milliliter bottles of the drug from the Las Vegas pharmacy as part of an order costing $853.