Hong Kong police have broken up a criminal syndicate after they rounded up 46 people and shut down its seven gambling dens which offered arcade machines with fishing games for betting.

The force said on Friday that the 31 men and 15 women, arrested the previous day, included the alleged ringleader and his wife, who were also accused of laundering about HK$10 million (US$1.3 million) in illicit gambling proceeds in a year.

Chief Inspector Chiu Peng-fai of the Mong Kok district crime squad said after an extensive financial investigation, police had frozen around HK$6.7 million in assets belonging to the couple.

He said police also impounded a seven-seater car, valued at about HK$410,000, which was bought by the 46-year-old ringleader with suspected crime proceeds.

“Investigations revealed that the criminal gang had recruited people from the same hometown in mainland China to come to Hong Kong as operators of gambling establishments,” Chiu said.

“The gang also arranged accommodation for these people to live in the city.”

After gathering evidence, police raided and closed down seven gambling venues controlled by the syndicate in Mong Kok, Kowloon City and North Point at daybreak on Thursday.

Officers also raided a Kowloon City flat used by the syndicate as a dormitory for the keepers from the mainland. Officers also raided an industrial unit in the same district, which were used to store arcade machines.

During the operation, police arrested 44 people on suspicion of operating a gambling establishment or gambling unlawfully.

Thirteen of them were the alleged ringleader, his wife and suspected operators who included seven visitors from the mainland. The 31 others were gamblers.

Officers also seized 47 arcade machines, more than HK$22,000 in cash and related documents.

Chiu said the ringleader, his wife and two holders of bank accounts were also detained on suspicion of money laundering.

As of Friday afternoon, all the suspects were being held for questioning.

Police said the investigation was still ongoing and did not rule out further arrests.

In Hong Kong, gambling unlawfully carries a maximum penalty of nine months in jail and a HK$50,000 fine. Operating an illegal establishment could lead to seven years in prison and a HK$5 million fine. Money laundering is punishable by up to 14 years in jail and a HK$5 million fine.