The DEA is investigating the origin of the medication

By George Stark
Updated April 27, 2016 at 12:00 PM EDT
Kevin Winter/Getty Images

Prince was found with prescription painkillers in his possession when he died, according to a new report.

NBC reports that the county sheriff investigating his death is now asking the Drug Enforcement Administration to help with the investigation.

Federal law enforcement officials who spoke to NBC did not reveal what part the medications may have played in Prince’s death. Officials say the DEA will help determine the origin of the medication and what prescriptions the singer had obtained.

Sources confirm to PEOPLE in this week’s cover story that Prince once had a history of using the prescription painkiller Percocet.

An autopsy of Prince’s body was conducted just one day after he was found unresponsive in an elevator at his famed Paisley Park estate outside Minneapolis. While the medical examiner found “no obvious signs of trauma,” toxicology reports may take weeks to complete.

Other sources tell PEOPLE that the “Raspberry Beret” singer had also been struggling with an “ongoing illness” at the time of his shocking death — just under one week after his private plane made an emergency landing in Moline, Illinois so that he could be rushed — unresponsive — to the hospital to receive what several reports called a “save shot.”