Police have arrested six people for illegal bookmaking and money- laundering involving more than HK$53 million.
Officers confiscated betting orders on soccer matches and horse racing with a face value of HK$5.2 million and seized computers, bank accounts and documents.
Detectives from New Territories South regional crime unit are still investigating whether the five men and one woman, aged between 30 and 40, worked for the same syndicate.
An officer involved with the investigation said: 'We believe they also helped to launder money in proceeds from illegal bookmaking activities through their bank accounts.
'Officers examined the bank accounts of the six suspects and found more than HK$53 million had been moved through the accounts during the past two years,' the officer said.
Each transaction involved hundreds of thousands of dollars.
Last night detectives were still investigating whether the suspects collected bets through computers, as intelligence showed that they had not collected bets over the telephone.
Officers began the investigation about six months ago and started making arrests on Saturday.
The latest arrest was made in Tuen Mun at 10.30pm on Wednesday. Officers arrested a 40-year-old woman and confiscated betting orders totalling HK$300,000 in her flat in Wu Kwong House, Wu King Estate.
Police suspect the public housing flat was being used as an illegal off-course bookmaking centre. Another investigator said millions of dollars had been moved through her bank account in one year.
The six have been released on bail pending further investigations.
The city-wide operation against illegal bookmaking ends on Wednesday. The racing season began last Sunday and Champions League football matches started this week.