$40 million

A 90-year-old Hong Kong woman was conned out of $40 million by fraudsters posing as Chinese officials, in the biggest phone scam recorded in the city's history.

According to The Guardian, the criminals contacted the unnamed woman in July, pretending to be mainland Chinese security officials. The fraudsters claimed that the 90-year-old's identity had been used in a serious criminal case, and told her that she needed to transfer money from her bank account into those held by an investigation team.

Through 11 transactions, she transferred millions into three accounts from August to January. One of the fraudsters even accompanied the victim to a bank to make one of the transactions, the police source said. The scam was only spotted because the elderly woman's domestic helper believed something suspicious was going on. She alerted her employer's daughter, who then urged her mother to make a police report. But, by then, $39.9 million had vanished, The New York Times reported.

Hong Kong police announced on Tuesday that a 19-year-old university student had been arrested. He was held on suspicion of “obtaining property by deception and released on bail, but police did not rule out further arrests, according to the Times.