SINGAPORE - A woman who plotted to kill her then husband has been sentenced to five months' jail.

Administrative assistant Amanda Yeo Pei Min, 27, had conspired with her 25-year-old boyfriend - delivery assistant Leong Wei Guo - to sabotage her spouse's car so that he would be killed in a traffic accident.

On Wednesday (March 11), Deputy Public Prosecutor Houston Johannus told District Judge Chay Yuen Fatt that Yeo had been "fuelled by malice and rage" towards her then husband - Mr Walter Ting, 28 - who worked as a private-hire car driver.

In urging the judge to sentence her to five months' jail, the DPP stressed that she was the mastermind behind the plot.

He also asked for a four-month jail term for Leong, adding that he had committed the offence due to a "foolish sense of bravado".

Judge Chay agreed with the DPP and sentenced Leong to four months' jail.

Leong and Yeo had each pleaded guilty on Feb 20 to working together and agreeing to cause grievous hurt to Mr Ting by performing a rash act.

The Straits Times understands that they are no longer together. Yeo is also divorced from Mr Ting.

Yeo married Mr Ting in September 2011, and they have two children.

But she later had an affair with Leong, which Mr Ting learnt about in June 2017.

"Walter wanted to divorce Amanda and they quarrelled frequently. Enraged by the acrimonious quarrels, she decided to kill Walter.

"She conspired with Leong to sabotage Walter's car so that he would get into an accident and die," DPP Johannus had said earlier.

Yeo told her boyfriend Mr Ting's death would "settle all her problems" and Leong agreed to kill him.

On Jan 6, 2018, Yeo told Leong to puncture Mr Ting's car tyres with some nails. In the wee hours the next day, Leong went to a multi-storey carpark near Mr Ting's flat in Yung Kuang Road, in Jurong.

With Yeo's help, he found the car and used a pair of pliers to insert a nail into each of its left tyres.

It is not clear if Mr Ting drove his car after this.

Yeo later discovered that her husband had made plans for a road trip with their children and his parents on Jan 11, 2018. She instructed Leong to loosen the wheel bolts on Mr Ting's car, which would be parked near his parents' flat, and cut the brake wires.

Once again, he agreed.

In the wee hours of Jan 11, 2018, Leong went to a multi-storey carpark near a Housing Board block in Depot Road where Mr Ting's parents live, and tried but failed to loosen the wheel bolts.

After that, he used a wire cutter to cut the anti-braking system wire behind the front right tyre and sent Yeo a picture of the damage.

"A complete cut of the (anti-braking system) wire will compromise the safety of the driver as the need to apply hard (or) emergency brake cannot be foreseen.

"The front right wheel of the motor car may lock, and this would pose a safety risk to the driver as he may lose control of the car," DPP Johannus said.

Leong was spotted walking around suspiciously with a jacket draped over his head and the police were alerted.

Officers arrived soon after and arrested him.

For committing the offence, Leong and Yeo could have each been sentenced to up to a year's jail and a maximum fine of $2,500.