SINGAPORE – More than 70 people received letters of extortion containing manipulated photographs of themselves in lewd poses in March and April.

At least one victim, aged 50, lost $20,000 after transferring the sum to the sender, who threatened to “leak” the pictures online.

The letters were sent to recipients’ workplaces and warned of “threatening consequences” if they did not contact the e-mail address provided, the police said on April 19.

Once victims made contact, the sender would threaten to release the obscene pictures on social media unless victims paid them.

The photographs and workplace addresses of the blackmailed victims were likely obtained from publicly available sources online, the police said.

With advancements in artificial intelligence-powered editing tools, manipulated pictures and videos may increasingly be used for extortion, the police added.

The police advised that anyone who receives such faked images should remain calm and ignore orders to initiate contact or transfer money, and make a police report immediately. The letter should be put in a separate storage bag and passed to the police.

Prime Minister Lee Hsien Loong, on Dec 29, warned the public in a Facebook post not to respond to scam videos on investments or giveaways after a deepfake video of him purportedly promoting an investment surfaced. It is not known who was responsible for the campaign.

Deputy Prime Minister Lawrence Wong, whose appearance has also been used to promote investment scams, alerted the public on Dec 11 of deepfake posts spreading rumours that the authorities were planning a circuit breaker amid a spike in Covid-19 cases.

The likeness of Ms Ho Ching – PM Lee’s wife and former Temasek chief executive – was also manipulated by fraudsters in another investment video that surfaced in December.