A post-mortem examination will take place on Friday on the body of Prince, after the pioneering musician died at his home aged 57 amid reports he was treated for a drug overdose just days before his death.

Tributes continued to pour in from around the world for the pop superstar, who died after being found collapsed in a lift at his home in Minnesota. A cause of death was not immediately determined and police are investigating.

The singer - real name Prince Rogers Nelson - was confirmed dead at Paisley Park in Minnesota, days after being rushed to hospital after falling ill on tour. His body was found unresponsive at the estate where he lived and worked in a recording studio.

TMZ, the American celebrity gossip site, claimed that the star had been treated for a drug overdose days before his death.

They said his plane made an emergency landing in Illinois on Friday so that the singer could be taken to hospital for a "save shot" - typically administered to counteract the effects of an opiate.

Doctors wanted him to remain in hospital, but when they were unable to provide a private room Prince and his entourage left. His publicists have not responded to the claims.