Customs officials have arrested two women and a man for suspected money laundering involving HK$61 million.

The arrests were made following a dangerous drug investigation last year and the discovery of suspicious transactions in the personal bank accounts of one of those arrested.

Further investigations then found large amounts of money had flowed through the bank accounts of the other two suspects, a 55-year-old woman and a 30-year-old man.

Acting senior inspector Au Wing-cheung of the Customs Financial Investigation Bureau said on Friday that transactions amounting to HK$61 million in suspected crime proceeds were recorded at bank accounts that the three had in seven local banks last year.

They could not provide reasonable explanations, he said.

"The suspects' bank transactions did not match their financial backgrounds," Au said.

"The three who were arrested claimed to be a catering employee, a housewife and a clerk when opening the bank accounts and to be on monthly salaries of HK$10,000 to HK$30,000.

"They also reportedly lived in public housing estates and did not own any properties.

"However, their bank accounts recorded more than 10,000 suspicious transactions amounting to HK$61 million," he said.

Two of them have been released on bail pending investigation, while the third involved in the drug case has been remanded in custody.

Au said Customs officers seized three mobile phones during the operation and that further arrests could be made.