At the age of 74, Mr Ng (not his real name) found himself heartbroken and destitute.
His only son cheated him of his only asset - a three-room flat - and left him to fend for himself.
To get by, the retired cleaner survives on two meals a day and stays with a distant relative.
His other child, a daughter, is mentally ill, unemployed and can be violent at times, he told The Sunday Times.
His wife is in a nursing home.
Earlier last year, his son, a blue-collar worker in his 40s, persuaded him to sell his flat and move in with his family.
He told Mr Ng he could keep the sales proceeds from the flat and use it for his daily expenses.
Said Mr Ng: "I was reluctant to sell but my son kept pestering me to sell."
He said he is not sure how much his flat was sold for, but his son told him that he would get an initial payment of $40,000.
The money never materialised.
Later, he found out his son took the amount as the son manages Mr Ng's bank account. His wife had entrusted their son with the couple's bank account and ATM card, Mr Ng said.
"When I asked my son what happened to the money, he said he spent it. I think he owes the banks money," he said.
"He told me not to harass him and he threatened to call the police if I keep calling him."
Mr Ng said his son hardly gave him any financial support in the past, even when he asked for it. He suffers from a host of ailments, including diabetes and arthritis.
Mr Ng has lodged a police report but said the police told him to file a civil claim against his son instead.
He thinks it is pointless to do so as his son would not be able to return the $40,000 to him anyway.
Social workers from TRANS Safe Centre, a charity which works with seniors who have been abused by their loved ones, have helped him close the bank account that his son had access to.
Said Mr Ng: "My son is very ruthless."