Officials probing the death of iconic singer Prince found a prescription opioid medication on his person, a law enforcement source told CNN Wednesday. The report came at a time of heightened speculation over the singer’s death April 21 at age 57.

The source told CNN that the opioid pills are usually taken to treat pain and that investigators have sought assistance from the U.S. Drug Enforcement Administration. According to the investigators, a reaction to the medication could have triggered a health scare about a week before Prince’s death, which resulted in an unscheduled landing of his plane in Illinois, the source said.

Prince was found unresponsive at Paisley Park, his home and studio in Chanhassen, Minnesota. An autopsy was conducted on the singer's body Friday at the Midwest Medical Examiner’s Office in Ramsey, Minnesota, and investigators are waiting for results to understand his cause of death. The autopsy results reportedly could take weeks.

Prince was cremated Saturday in a private ceremony attended by family members and close friends. Prince's sister, Tyka Nelson, her son President LenNard Laeil Nelson and an unidentified third person were seen retrieving Prince’s ashes Monday.