A 90-year old woman from Hong Kong has been scammed out of HK$250 million (£23m, $32m) by fraudsters pretending to be Chinese officials, police said.
Hong Kong police said the criminals had posed as public security officials investigating a criminal case in China.
The woman was told her identity had been stolen and used on the mainland.
She was then coerced into making 11 deposits to a bank account between August and January - to help the alleged investigation.
So far, investigators have arrested a 19-year old man who has since been released on bail.
According to local media the woman was first contacted in August last year by someone pretending to be a mainland official.
The scammers then went to her place and gave her a phone she was to use to communicate with them.
The entire incident was only uncovered when the woman's domestic helper alerted her employer's daughter about the unusual activities.
The old woman had been living without family but with several domestic staff in her house in Hong Kong's most affluent neighbourhood, The Peak.