When a man claiming to be a Manpower Ministry (MOM) official called to warn that he was facing deportation, Mr Chaudhuri, an Indian national working as an academic researcher here, believed him.
The caller rattled off Mr Chaudhuri's full name, Foreign Identification Number, date of birth, when he arrived here and a case number. Even the caller's phone number - 64385122 - was the same as MOM's contact centre hotline.
After scolding Mr Chaudhuri for providing the incorrect date of birth in an embarkation form, the man provided a simple "solution". All Mr Chaudhuri had to do was pay a "refundable" fee of $1,000, which will be returned the same evening. He ended up paying $2,000 before he realised it was a scam and lodged a police report.
Mr Chaudhuri (not his real name) was not the only such victim.
The police issued a crime advisory last Friday warning of scammers who use a number that appears to be the MOM's hotline to warn victims of errors in their personal particulars. To settle issues relating to their stay in Singapore or work pass, the victims were then told to transfer money to an account.
From April 29 to May 22, there were 37 such cases reported.
Police said 15 victims have lost more than $31,000 this way, with the amounts ranging from $1,000 to $5,000 each.
The scam is similar to a spate of cases last year when conmen pretending to be Immigration and Checkpoints Authority of Singapore officers cheated more than 60 victims.
While some of the victims in this latest scam realised they were being had and lodged police reports without paying up, Mr Chaudhuri was not as fortunate.
"He threatened me, but then he gave me the solution," said the 32-year-old employment pass holder of the May 12 incident.
"Anybody would have agreed with him if you believe he was from MOM, because nobody wants to disrupt their work because of legal problems."
After he agreed to the "refundable" fee, Mr Chaudhuri received a second call. The same scammer told him that the call was being recorded, and that if he put down the phone, the police would be informed.
Mr Chaudhuri was then transferred to a "colleague" from the finance department, who directed him to a SingPost outlet to transfer the money via Western Union.
After transferring $1,000, Mr Chaudhuri was asked to transfer another $1,000, purportedly to the Indian government to assist with his case. He complied.
It was only when he was asked for another $1,000 that Mr Chaudhuri realise he had been cheated. He ended the call and went to the police.
"They had planned this in a very systematic way: they knew my occupation, and also told me to confirm online that they were calling from an MOM number," he said, adding that the scammers sounded local and professional during the 50 minutes they kept him on the phone.
An MOM spokesman said the ministry does not ask for payments over the phone, and that fees are either paid at its office, or through an official written notice.
"MOM will not call members of the public to request any fund transfers."
Mr Chaudhuri hopes his tale will prevent others from falling victim to the same scam. "I don't know how somebody can use an MOM number to carry out this kind of fraud."