Hong Kong police have arrested 100 people in connection with a series of online scams, including a love scam in which a Canadian victim lost HK $23 million ($2.9 million) after falling for "sweet talk" from scammers.

Police said yesterday (May 3) that the week-long operation resulted in the arrest of 71 male and 29 female suspects, aged between 17 and 74. The suspects come from all walks of life, including clerks, salespeople, retirees and the unemployed.

They were alleged to have obtained property by fraud and money laundering in 63 cases totalling HK $81 million, with losses ranging from HK $550 to HK $23 million in each case.

A 60-year-old Chinese man has the most to lose after being duped by a scammer on social media, Canadian police said. Police arrested a 47-year-old man in Hong Kong in connection with the case as his bank account was used to collect HK $2 million of the victim's HK $23 million.

"This scammer used sweet talk to trick victims into investing. The victim made multiple transfers." Wan Chai district chief Inspector Shun Po-chun said.

She said many of the 100 suspects allowed the scam syndicate to access their bank accounts in order to collect and process the stolen funds. She also urged residents not to lend their personal or business accounts to others.

One of the arrested persons is a 39-year-old female fraud suspect who allegedly stole four credit cards from three victims and purchased goods totalling $210,000.

Police said they believe the thieves stole credit cards from residents who didn't pay attention to their personal belongings in crowded areas. The scammers then hand the cards to their accomplices, who make small purchases to check if the victim has reported the card stolen.

"Once they know there is no report, they immediately head to large chain stores to buy electronics, including laptops, cell phones and gift cards, which are easy to cash in at a profit." Inspector Cen said.

She warned residents to beware of scams, while urging traders to contact police if they encounter suspicious transactions.

"As the city returns to normal after the outbreak, the public should remain vigilant in crowded places and watch their personal belongings," she said.

The police added that there has been an increase in card fraud and theft cases in Wan Chai, reaching 37 cases in the first quarter of this year, more than double the 14 cases in the same period last year.

In Hong Kong, money laundering carries a maximum penalty of 14 years in prison and a HK $5 million fine, while the offence of obtaining property by deception carries a maximum penalty of 10 years in prison.

Last year, the police handled 27,923 fraud cases amounting to HK $4.8 billion.

More than 70% of cases last year were related to online fraud, with a total of 22,797 technology crimes reported, resulting in a loss of HK $3.2 billion. Telephone fraudsters committed 2,831 fraud cases amounting to more than HK $1 billion.