Veteran singing star Gene Pitney died of natural causes, a post-mortem examination has shown.
The 65-year-old American, who was in the middle of a 23-date UK tour, was found dead in his room at the Cardiff Hilton Hotel on Wednesday morning.
South Wales Police said the results meant his body could be flown back to the United States for his funeral.
He sang in Cardiff the night before and his management company In Touch said there had been no signs he was ill.
Pitney, whose biggest hits included Twenty Four Hours From Tulsa, was pronounced dead at the Hilton.
A police spokeswoman said there would be no inquest opened or any further police inquiries into the death as the post-mortem results indicated he had died of natural causes.
"As soon as it [the death] was deemed to be non-suspicious, the matter was handed over to the coroner," she said.
Pitney was staying in the Welsh capital after a standing ovation for his performance at St David's Hall on Tuesday night.
He was found in bed by Geoff Clennell, his former tour manager and long-term friend.
Gene Pitney was staying in an executive suite at the Hilton
Mark Howes, his tour promoter, said: "I just understand that he was asleep in bed.
"He was in bed in his pyjamas and there was no sign that he had struggled to get up or anything - that was what the paramedics told Geoff Clennell.
"It seems he just passed away in his sleep."
He added: "I just feel bad that his family are so far away."
Mr Howes said arrangements will now be made to fly Pitney's body back to his home in Connecticut for Friday or the weekend.
The singer's biggest success was in the 1960s and he enjoyed a 1989 revival with a chart-topping duet of Something's Gotten Hold of My Heart with Marc Almond, of Soft Cell fame.