According to police, 42 percent of the 3,000 inmates in Dubai's central jail are there because they did not repay bank loans.
The practice of jailing debtors more usual in 18th century England than in an ultramodern city illustrates the downside of this Gulf city-state's frantic boom.
Many people here struggle to make ends meet in a place flush with oil cash and real-estate money, with ever-taller skyscrapers, stretch limos, spacious villas and opulent shopping malls. Surrounded by so much wealth, many succumb to the temptations of a lifestyle they cannot afford.
Dubai's lack of a central credit-check authority, coupled with its lack of a personal bankruptcy court system and banks' willingness to give consumer loans with virtually no collateral, have prompted even the police to complain that something must be done.
"If they cannot pay, we cannot release them," said Lt. Col. Abdulhalim Mohammed al Hashimi of the Dubai Central Prison.
The case of Mubarak, a 28-year-old Emirati, is typical. He was working 12-hour shifts as a crane operator in Dubai's port when he took his first bank loan to buy a car and furniture.
Even though he fell behind in the payments, he still managed to get two more loans from two different banks, each bigger than the one before.
He used one loan to pay off another but stopped making payments on the two others. After he ignored court summons, the bank deposited the blank check that he had presented as his sole collateral.
The check bounced and he was sentenced to three months in jail. He'll stay there longer if no one steps forward to pay the US $44,700 (euro33,250) debt.
In the United States, such a case would head to bankruptcy court, where the debtor would have a chance to sell off assets and restructure some debts to slowly pay them back.
But in Dubai, with no laws regulating defaults on personal borrowing, a person jailed for such an infraction is likely to remain there even when their sentence is over until a relative, charity group, wealthy businessman or even a member of the ruling family pays off the debt.
Police official Mohammed Murad complained that 60 percent of the police force is busy chasing deadbeats and chides banks for promoting rampant consumerism with easy cash. He contends banks would be more careful with loans if they had to share the cost of imprisoning debtors.
"Each one of them costs as much as someone in a five-star hotel," Murad said.
Critics also say that banks do not routinely advise customers of their responsibilities. Banks ask for undated, blank checks as collateral rather than property, which could be appraised and seized for nonpayment.
But the banks defend themselves.
They, lawyers and the police blame the problem in part on the absence of a central credit authority, which could alert lenders to high-risk customers.
The Central Bank has promised to establish a credit authority by the end of the year.
"The notion that these people in jail are poor lambs being preyed upon is rubbish," said Louis A. Scotto, general manager of Emirates Bank. "We are not the bad guys here."
Scotto said banks do not turn to customers' blank checks except as a last resort. Dubai's police say once that happens, there is little choice.
"They signed a check without balance. That is a crime," said Khalid Ahmed Omer, legal adviser to the Dubai police. "If there is no check, no one can take you to jail. But if you signed a check, you are responsible, not the bank."
Last year, banks here granted US $43 million (euro32 million) in personal loans many with only an undated blank check as collateral.
Some fear the problem will only worsen.
"It's a way of life here," said lawyer Abdullah al Nasser. "If money comes easy, no one will pay it back. And if I have a choice between a Toyota or a Mercedes, of course I will choose the Mercedes."