He was married, an undischarged bankrupt and the manager at a laundry outlet, but he told a woman 17 years his junior that he was single and the heir to the family laundry business. Leslie Khoo Kwee Hock also got Ms Cui Yajie to hand him $20,000 to invest in gold.

Their rocky relationship came to a grisly end when Khoo strangled the Chinese national while they were in his car at Gardens by the Bay. He burned her body in Lim Chu Kang Lane 8, returning to the scene over the next three days to add charcoal and kerosene.

When Khoo, 50, led police to the scene after his arrest, he smiled and said there was "nothing left", the High Court heard on the first day of his murder trial yesterday.

Khoo, who faces the possibility of hanging, does not dispute that he killed Ms Cui, a 31-year-old senior engineer with a semiconductor company, on the morning of July 12, 2016.

His lawyer, Mr Mervyn Cheong, told the court that Khoo would be relying on diminished responsibility, sudden fight, and grave and sudden provocation to establish that the killing did not amount to murder.

However, Deputy Public Prosecutor Tan Wen Hsien painted a picture of Khoo as a serial swindler who cheated several women of their money and feelings by asking them to invest in his business.

DPP Tan has lined up Khoo's past lovers and "investors" as witnesses to establish the case that he killed Ms Cui because she was closing in on his lies. "He had every intention of silencing her," she said.

In the days leading up to her death, Ms Cui contacted Khoo's wife - whom she believed he had divorced - and told her to leave him alone. She also demanded that Khoo return the $20,000 she had entrusted to him for investment and threatened to confront his bosses at work.

"The accused saw the house of cards he built crumbling," said the DPP, adding that Khoo wanted to stop Ms Cui from "setting off a train of inquiry" against him, including the fact that he owed her money, swindled $65,000 from four other women and misappropriated $24,000 from his employer.

In allowing the testimony of these witnesses, Judicial Commissioner Audrey Lim said that there were no eyewitness to the killing and the case rested on Khoo's account of events and circumstantial evidence.

DPP Tan said the pair entered into a relationship in 2015 "founded on a bed of lies".

At first, Khoo, who has a son, told Ms Cui that he was single, but when her suspicions were later aroused, he told her he was divorced. He was a retail outlet manager for a laundry company but told her that it was his family business.

As time went by, the lovers had frequent quarrels over Khoo spending too much time with his "former wife" and son, and the money that Ms Cui "invested".

In July 2016, facing pressure to return the money, Khoo asked a former lover, also a Chinese national, to remit $10,000 to the bank account of Ms Cui's father. When Ms Cui realised she received only half her money back, she had a heated quarrel with Khoo.

Meanwhile, Khoo's wife confronted him for cheating on her, after Ms Cui sent her a Facebook message telling her to stay away from him.

In the early hours of July 12 that year, after Ms Cui threatened to speak to his bosses, Khoo picked her up from Joo Koon MRT station in his car so he could take her to meet his supervisor, said the DPP.

But instead, he drove her to a secluded location at Gardens by the Bay and, in the parked car, strangled her in the front passenger seat.

According to Khoo, after Ms Cui stopped moving, he lowered the seat and covered her body with laundry bags to hide it from view.

Khoo admitted that he decided to burn her body and bought significant quantities of charcoal and kerosene from two shops in Kranji Road. He then went to Lim Chu Kang Lane 8, placed the body under a metal canopy, and burned it.

Over the next three days, he returned to add more fuel and ensure that the body was burning well.

When Ms Cui did not turn up for work by July 14, her colleagues lodged a police report.

Khoo was arrested on July 20.

Clumps of hair, pieces of fabric similar to the dress that Ms Cui was last seen in, and a bra hook were all that were recovered from the scene.