Cheltenham Coroners' Court heard the 57-year-old was found dead in a hotel room in Las Vegas on 27 June of a suspected heart attack.

Deputy coroner Dr Sophie Burrows adjourned the hearing until further tests were available to submit as evidence.

Floral tributes were left at the hotel

Although Entwistle, who lived in Stow-on-the-Wold, died in the US it is policy for an inquest to be held in the UK for all British residents.

A post-mortem found there were signs of significant natural pathology but conclusions on the causes of death could not yet be drawn.

Entwistle, affectionately known as The Ox, had been in Las Vegas for the start of The Who's US tour, due to start the day after he died.

The Who have millions of fans worldwide

The Hard Rock Hotel, where he was found, was due to be the venue for the band's first night but this was cancelled following the announcement of Entwistle's death.

But the tour has now begun after remaining members Roger Daltrey and Pete Townshend decided the show must go on. They have dedicated performances to their late friend, with the full blessing of Entwistle's family.

Session bass player Pino Palladino stepped in at the last minute to replace Entwistle.

Entwistle's sudden death came almost 25 years after The Who's original drummer, Keith Moon, died of an accidental drug overdose.

Fans watched The Who rehearsals for the tour on giant screens

The Who first formed in London in 1964 and were one of the leading rock bands through the 1960s and 70s scoring hits with Pinball Wizard and My Generation.

Entwistle, born in Chiswick, London, paired up with The Who front man Roger Daltrey in a forerunner to the group in the early 1960s.