Licensed as sports clubs, these establishments offer a unique set of games at night, as young businessmen and politicians gather there to gamble.
Business at two such casinos – Fakirapool Young Men's Club and Dhaka Wanderers Club – had been in full swing within 100 yards of the Motijheel police station.
However, Dhaka Metropolitan Police seemed to have discovered these illegal gambling spots only after Rapid Action Battalion (RAB) unearthed them on Wednesday during a raid.
DMP Commissioner Mohammad Shafiqul Islam said they are making a list of these casinos and will shut them down, no matter how powerful the people behind those are.
"I want to make it very clear that I will not allow anyone, be it a person from an influential group, to run these illegal businesses," the metropolitan police chief said at a briefing on Thursday.
On Wednesday, RAB raided at least five illegal casinos where crores of taka were being gambled away every night.
Social activists and political leaders said no one could have run illegal casinos for so long without help from the law enforcement agencies.
They also sought thorough investigation into the matter.
But local police officials denied such allegations, and said they were not aware of these activities.
A senior DMP official, seeking anonymity, claimed that in order to combat or run a drive, the police needed political approval.
"Without political support, the police alone will not be able to combat such illegal activities," he added.
The officer also admitted that some policemen were involved in this racket, and speculated that local police officials must have known about these activities.
"If local police were not aware of people running illegal casinos right under their nose, they should not be working as police officers," he added.
Sarwar Bin Kashem, director of RAB's legal and media wing, said they had uncovered several names involved in the racket – most of whom are ruling party allies.
He said: "We got a lot of information during primary interrogation, including how they ran the business, who were behind it, and where the illegally amassed money was laundered abroad. We cannot disclose all this information at present."
Who are they?
Following the drive, several intelligence and law enforcement agencies are now making lists of illegal casinos run in various clubs in Dhaka.
Dhaka Wanderers Club is owned by Mollah Md Abu Kawser, president of Awami Shechchhasebok League.
AK Mominul Haque Saeed, commissioner of Dhaka South City Corporation's Ward 9, runs gambling dens under the guise of clubs – Arambagh Sporting Club, Mohamedan Sporting Club and Dilkusha Sporting Club.
Dhaka City South Jubo League President Ismail Chowdhury Somrat runs an illegal casino at Victoria Sporting Club.
Dhaka City South Jubo League Organising Secretary Khaled Mahmud Bhuiyan used to run Fakirapool Young Men's Club, until his arrest during RAB's raid.
Parliament member and Bangladesh Workers Party President Rashed Khan Menon is the chairman of the governing body of the club.
However, Menon has denied any involvement in such illegal activities, saying he only knew that the club was for cricket and football matches.
"I was not aware about these casinos," Menon said.
An intelligence report by the DMP found that some ruling party's front organisation leaders have been running these illegal casinos.
The report also stated that both Somrat and Khaled collected large sums of money from these casinos daily. Their goons protected the establishments.
A home ministry source informed The Business Standard that at least 50 such clubs are operating in the capital, of which around 20-25 are running illegal casinos with the help of ruling party leaders and police members.
According to a home ministry report, other clubs involved in this racket are: FuWang Club in Gulshan, Dhanmondi Club, Soinik Club in Paltan, Uttara Club, Ezaz Club on Elephant Road, and the Kolabagan Club.
How did the casinos operate?
These clubs are officially open from 10am to 5am the next day.
However, locals claim that they are open for 24 hours, and are frequented by businessmen, politicians, and media personalities.
An employee working at one of the casinos said customers spent from Tk5 lakh to Tk2 crore each in one night.
"Ruling party leaders and activists received money from this casino. They also gave shelter and protection to the participants," he added.
Seeking anonymity, a Motijheel resident said nobody is willing to speak about these casinos. "I was beaten up by ruling party activists as I once spoke out against these before."