A human rights charity has accused Dubai police of beating and electrocuting three British men who are awaiting trial on drugs charges.
Grant Cameron and Karl Williams, from London, and Suneet Jeerh, from Essex, were arrested on holiday last July.
Police said they had found synthetic cannabis known as "spice" in their car.
The three men, all 25, signed documents in Arabic they did not understand after being threatened with guns, the charity, Reprieve, said.
The men, who deny a charge of "consumption and possession with intent to distribute" in relation to the cannabis, are due in court for their first trial hearing on Thursday.
'So scared'
They have spent seven months in custody pending trial.
Reprieve lawyer Marc Calcutt said the men could face up to four years in prison if convicted of consumption, or between 10-15 years if convicted of possession.
"Under certain circumstances they could be sentenced to death", he added.
According to Mr Calcutt, in a draft witness statement given to him, Mr Williams said: "I remember that the police put a towel on my face so I could not see. They kept telling me I was going to die. I was so scared."
Mr Williams said he was placed on a bed and then had his testicles electrocuted.
"It was unbelievably painful. I was so scared," he said, according to the statement.
"Then they took off the towel and I could see that there was a gun pointed at my head. All I could think was that the gun in my face could go off if the policeman slipped, and it would kill me. I started to believe that I was going to die in that room."
The torture took place in the desert, it is alleged, where the men were initially taken after their arrest, and then later again in a hotel room.
Mr Cameron's father Phil told BBC Radio 5 live: "When they were arrested it was... quite surreal, horrible experience. He's been away from us now for nearly eight months.
"It's just a terrible experience - he wasn't allowed any water... we didn't know what to do, how to help him."
Inquiry call
He added his son's holiday in Dubai had "gone very, very wrong for him".
"He had a great career, a wonderful girlfriend - all his friends and neighbours are hoping he'll come back to us soon."
Mr Williams and Mr Cameron are being held at a police station, while Mr Jeerh has been moved to a jail.
Mr Calcutt told the BBC: "They still don't know what they have signed and what they have admitted to."
He hopes Reprieve will be given access to the documents soon, but in the meantime has called on the United Arab Emirates government to launch an independent inquiry into the alleged torture, adding that he fears the men have been "fitted up" by police eager to secure an arrest.
The BBC has contacted the United Arab Emirates embassy in London but has not yet received a response to the allegations.
