A 24-year-old mainlander living in a partitioned flat in Sham Shui Po was arrested yesterday for laundering HK$567 million between 2010 and last year.
The self-declared company director stayed in Hong Kong on a two-way permit and allegedly laundered the money through cash deposits and bank transfers, police said.
There was a firm registered under his name, but it was a shell company that had no actual business in operation, they said.
Officers found no signs of a functioning business when they visited its office in Central.
"Most of the funds [deposited] were of unknown origins and show signs of money laundering," detective chief inspector Lam Cheuk-ho, of the Kowloon East regional crime unit, said.
Lam said the suspect might have acted as a front for local or cross-border clients, possibly involving criminal syndicates, between mid-2010 and mid-2012.
Police believed he acted alone and handled all the transactions himself, as officers had found no one else involved in laundering the money. The police first detected suspicious funds flowing into the shell company when officers were investigating a local couple who laundered about HK$130 million for mainland clients betting at gambling dens they operated in Fortress Hill.
In February, the man, 43, was jailed for 18 months while the woman, 39, received a 15-month suspended sentence.
Similar methods of money laundering were employed in both cases, using cash deposits and bank transfers, police said.
In January, another mainlander was sentenced to 101/2 years in jail over the city's largest-ever money laundering case.
Luo Juncheng, 22, laundered a record HK$13.1 billion over eight months between September 2009 and April 2010 through a shell company established in Hong Kong in July 2009.
In handing down the sentence, the judge urged the government to review whether existing laws and punishments were adequate to deter money laundering activities, in view of the growing scale of such crimes in recent years.
The city froze HK$1.39 billion in crime proceeds under court orders last year, the largest amount in three years, and 166 people were convicted of money laundering, the Department of Justice said in August.