A British tourist who died in police custody in Dubai choked on his own vomit, the Gulf emirate's attorney-general said today.
Lee Brown, 39, was arrested after being accused of physically and verbally abusing a female member of staff at the luxury Burj Al Arab hotel, the local authorities said.
He died on Tuesday amid claims that officers punched and kicked him during his time in custody at Bur Dubai police station.
Dubai attorney-general Issam Al Humaidan said a post-mortem examination found Mr Brown's death was caused by suffocation after vomit leaked into his respiratory tract.
Offering condolences to the Briton's family, he stressed in a statement that police in the emirate dealt with prisoners with respect and were "governed by the highest standards to preserve human rights".
British diplomats and human rights campaigners demanded a thorough investigation into the tragedy.
Mr Brown's family in Dagenham, east London, were told he had allegedly suffered severe beatings in custody after another prisoner found their contact details on a photocopy of his passport left in a cell, the Daily Mail reported.
His relatives contacted the British Embassy in Dubai with their concerns about his safety.
But UK officials who visited the police station were told he did not want to meet them, according to the founder of a support group for alleged victims of injustice in the United Arab Emirates.
Radha Stirling, from London-based Detained In Dubai, said: "Really, they should have been able to see him to make sure he was in a good condition, whether or not he wanted to speak to them.
"It does look like he was in a bad condition and the police didn't want the embassy to see him. It's quite a failure of process."
She said other people held at Bur Dubai police station had told her it was known for its filthy cells, harsh conditions and violent attacks on prisoners.
Mr Brown was said to be on a last-minute holiday at the Burj Al Arab, which describes itself as "the world's most luxurious hotel" and where room prices start at more than £1,000 a night.
Hotel operator Jumeirah Group said in a statement: "We are aware of this issue and understand it is being handled by the relevant authorities. We therefore have no further comment.
"For privacy reasons, it is our policy not to disclose any details or information about guests who stay in our hotels."
Dubai police said Mr Brown had no bruises or marks indicating an assault when he died, according to The National newspaper in neighbouring Abu Dhabi.
An unnamed police official told the paper: "These reports in the media that he was beaten by police are a pack of lies."
The official added that the British tourist began vomiting the day before his death but did not complain or ask for medical help.