Authorities on Thursday said they are stepping up efforts to tackle scam syndicates and their use of mule accounts to launder funds.

This came after the number of scam cases rose by 12 percent, to almost 45,000 last year, involving more than HK$9 billion.

Some 8,600 people were arrested on suspicion of lending their bank accounts for money laundering in 2024, a jump of 44 percent from the previous year.

Among the new measures, police will be sharing with banks the account and phone numbers, as well as e-mails associated with suspicious bank accounts on its Scameter database.

The Hong Kong Monetary Authority (HKMA) said banks could flag suspicious accounts, and when money goes into them, they can consider reminding clients of risks, conduct further vetting, or ask police for help.

Subject to Legco's passage of a new law, local retail banks will also seek to step up data sharing of suspicious accounts and transactions by the end of the year.

An executive director of the HKMA, Raymond Chan, said authorities and the sector will take steps to protect the privacy of clients.

"Banks will only be sharing client information in specific situations such as scams and money laundering. The information can only be used for detecting and preventing banned activities," Chan said.

"The sharing can only take place on a designated platform. One of the platforms is the Financial Intelligence Evaluation Sharing Tool (Finest) set up by the police."

Chan said the HKMA and the force will closely monitor the information sharing system, and it will be issuing guidelines to banks on its use.

Meanwhile, a police chief superintendent, Kelly Cheng, said officers had taken steps to tackle cross-border scam cases.

She noted that in a joint operation spanning several months last year, mainland authorities arrested 251 people in connection with more than 500 scam cases.

The arrestees – most of them from the mainland – were suspected of coming to Hong Kong to open bank accounts before going back across the border.