Bank employee Jeffrey Tan considers himself to be savvy in making financial investments.
But last December, the 30-year- old began putting $20,000 in an offshore sports arbitrage betting company and went on to lose half of it.
He also persuaded about six friends and his parents to invest about $200,000 in all. They lost all their money.
"I felt so guilty for dragging them in that I tried to kill myself," he said, showing The Straits Times a letter from Tan Tock Seng Hospital, where he was hospitalised for depression after taking an overdose.
He claims to have fallen victim to a sports betting syndicate run by 33-year-old Singaporean Alvin Ang Jun Bin, who claimed to be representing Isle of Man-registered offshore betting company Keystone Trading in Singapore. He has made a police report against Mr Ang.
Police confirmed that more than 20 reports have now been lodged against Mr Ang. The alleged victims, mostly in their 20s and early 30s, have set up a WhatsApp chat group to share information.
Their losses are estimated to total more than $1 million, according to fellow victim Lau Cheng Yi. The 22-year-old, who runs a food and beverage business, lost about $55,000 in cash and three luxury watches valued at $72,000 in total.
"He promised returns of 2 to 10 per cent every month," said Mr Lau. "I did not get a single cent and he is now uncontactable."
Mr Lau said he met Mr Ang in March at a roti prata restaurant in Upper Bukit Timah. "He came in a Nissan GTR sports car and was wearing Louboutin shoes and a Rolex watch," Mr Lau said.
Attracted by the promise of "risk-free returns", Mr Lau handed over his Audemars Piguet Las Vegas watch worth more than $30,000 on the spot. A day later, Mr Ang opened an online account for Mr Lau at the Keystone Trading website with 20,000 credits to his name.
Over two more months, he progressively invested more money after being persuaded. By June, he had put in $127,000.
He sensed something was amiss that month when the website was down. He met Mr Ang at the void deck of his Bangkit Road Housing Board flat. He said Mr Ang claimed that his boss - "Sky" - had run away with the money and promised to look for him to return it.
Other victims said Mr Ang assured them the betting programme was legal as the bets were not placed in Singapore, but through Keystone Trading's offices located in Shenzhen, China, and the United States.
Mr Ang's mobile line was disconnected and he did not reply to messages to his phone.
When reporters visited his HDB flat in Bangkit Road, his father said he moved out last year and came home only occasionally.
Asked if his son was overseas, he said: "I will also avoid people if I were him. Why you ask so many questions?"
Police did not have figures for investment scams specifically. There were a total of 5,150 cheating cases from January to September this year, while the whole of last year saw 6,560 cases, up from 3,898 in 2014.
Mr Tan is now coping with his depression, but the episode has taught him not to be lured by promises of easy money. "I paid a price for learning this," he said.