Prince died of an opioid overdose, according to a law-enforcement official.

However, no cause of death has yet been revealed by the Midwest Medical Examiner's Office, which told Entertainment Tonight there is "nothing to share at this time."

It was previously claimed that Prince had been addicted to the painkiller Percocet for years because of problems with his hips and that he had to be given a "save shot" almost a week before his passing after he overdosed on the highly-addictive drug, which contains acetaminophen and oxycodone

Prince - who had used a cane to help him get around for many years - had long needed a double hip replacement but reportedly turned it down on numerous occasions but he was worried it would require a blood transfusion, which would have conflicted with his beliefs as a Jehovah's Witness.

The singer was rushed to hospital in Moline, Illinois on April 15 for the shot, which is administered to counteract the effects of opiates, after being taken ill on his private jet on the way back from a gig in Atlanta.

Prince died the day before he was reportedly due to meet with Dr. Howard Kornfeld, a national authority on opioid addiction treatment, about his addiction to painkillers.

Attorney William Mauzy, speaking on behalf of the Kornfeld family, has previously explained that while Howard could not travel from California immediately, he sent his son Andrew to go ahead and speak to Prince about his problem before he flew out the following day.

Mr Mauzy said: "The plan was to quickly evaluate his health and devise a treatment plan. The doctor was planning on a lifesaving mission."

However, when Andrew arrived at Prince's Paisley Park estate on April 21, Prince was nowhere to be found and he and two of the star's employees eventually found him unresponsive in an elevator.

According to Mr Mauzy, Andrew said the employees screamed when they found Prince and "were in too much shock" to call 911.