The suspects, nine men and five women aged between 23 and 56, were arrested during a two-day operation codenamed "Flydust."

The syndicate used a shell company in a Fo Tan industrial unit that controlled the bank accounts to "whitewash" more than HK$380 million in illegal proceeds over 18 months.

The suspected mastermind and seven of his family members were among those arrested, police said.

Of the sum, HK$25 million came from 50 local and overseas scams committed between April last year and October, police said. "We are still investigating the sources of the remaining HK$355 million," said Chief Inspector Tang Hoi-tung, of the financial intelligence and investigation bureau.

"Of the 50 scams, 13 were phone scams, eight investment, four online romance, four e-mail and 21 others."

The biggest victim was a 30-year-old female clerk who lost HK$550,000 in an investment scam, Tang said.

In February, the victim met a male scammer online claiming to be living in the United States.

During the operation, police seized more than HK$370,000 in cash, 50 debit cards, phones, computers and bank documents.