Sam Dorman, 33, from Glossop, Derbyshire was arrested after a police sting last week. UAE police allegedly found him with only half a gram of cocaine.
Police later found what they believe is 28 grams of the drug at his home in Dubai.
In the UK the street value of 28 grams of coke is around £2,000. But in the UAE, which has a strict zero-tolerance policy on drugs, it is valued at up to three times as much.
The father-of-one was arrested last week and has already been jailed for 40 years on Monday, the Sun reports.
He is said to be held at the notorius Al-Awir Central Prison, which is situated on the outskirts of Dubai, which is known for its corrupt guards, filthy conditions and violent inmates.
“He’s got a young daughter in the UK, so to be serving 40 years is really sad,” A source told the newspaper.
“He won’t be out till he’s in his 70s.
“The prison’s a hellhole and Sam’s family are understandably distraught.
“When they spoke to him, it looked like he’d taken a battering. I just hope someone can help him.The barber and tattoo artist reportedly moved to the Emirate to start a business.”
He was allegedly arrested after selling cocaine to a customer, which is how the police are thought to have found him.
The source added: “He got in with the wrong crowd. Sam apparently sold coke to a customer who was pulled over and arrested by police.
“They took his phone and messaged Sam pretending to be the buyer and asked for more. Sam stupidly went and the police were waiting. At this point he was nabbed.”
The Foreign Office said: “We are supporting a British man detained in Dubai.”
