The autopsy for Prince has been completed, but completed toxicology tests are likely to take weeks, according to the Midwest Medical Examiners Office.

The pop star may have suffered a drug overdose less than a week before he died on Thursday. According to TMZ, Prince was using the painkiller Percocet to treat chronic hip pain tied to a 2010 surgery.

Prince’s jet plane made an emergency landing in Moline, Ill., last week due to a medical emergency. His rep told Variety at the time that the singer was struggling with the flu.

He was also briefly hospitalized.

On Thursday morning, authorities found Prince unresponsive in an elevator after responding to a 911 call. They tried CPR, but were unable to revive the pop star. He was pronounced dead at 10:07 a.m.

“We have no reason to believe it’s a suicide, the rest is under investigation,” said Sheriff Jim Olson at a press conference Friday.

There were no visible signs of foul play, he said.

The last time time Prince was seen alive was Wednesday night at 8 pm when he was dropped off at Paisley Park.

Earlier in the week, he visited a Walgreen pharmacy multiple times, a sign the multi-Grammy-winner was still dealing with a medical issue.

Police are continuing to investigate the circumstances surrounding Prince’s death.