SINGAPORE - The apex court made a rare ruling to grant judicial mercy to a woman with terminal cancer when it converted her jail term of one week for contempt for court to a $5,000 fine.

The mother of two took her case to the Court of Appeal after she was found guilty of breaching court orders to not involve her children in an "extremely ugly" divorce case.

The woman has stage 4 breast cancer, is wheelchair-bound and weighs only 30kg.

She was found by prison medical staff to be unfit for jail time, given the severity of her illness.

Judge of Appeal Andrew Phang, who delivered the grounds of decision earlier this month, said: "The exercise of judicial mercy, while not unprecedented, has only been done in exceptional circumstances. For the court to exercise mercy, there must be exceptional circumstances from which humanitarian considerations arise, outweighing the public interests in having the offender punished for what he had done wrong against the law."

Lawyer Dorothy Tan explained that in cases where judicial mercy is granted, the consideration of humanitarian reasons, such as terminal illness, overrides the need to make the appropriate sentencing measures befit the crime.

Justice Phang said the case was as an extremely ugly one where the mother waged an all-out war against her former husband, despite being diagnosed with breast cancer after she started divorce proceedings.

The judge said: "This included employing a scorched earth policy (a military strategy that seeks to destroy anything that could be useful to the enemy) that involved utilising the two children of the marriage as pawns in attacking their father."

He cited an earlier judgment of Family Justice Courts (FJC) Presiding Judge Debbie Ong, who noted the children used to have a loving relationship with their father. But the mother had "relentlessly polarised them against their father to such an extent that any repair of the relationship was not practically feasible".

The couple, who are in their late 40s and early 50s, have two children - a daughter, 15, and a son, nine.

The woman's male colleague, whom her former husband accused of being her lover, moved in with the woman and her children, purportedly to help her with cancer treatment. Justice Ong found the woman had actively allowed her colleague to manipulate the children against their father.

The man took his former wife to task for contempt of court for breaching court orders. These included getting both parents to not make disparaging remarks about the other parent to the children, and not involve the children in the divorce litigation, such as showing or discussing with them any court documents or correspondences related to the case.

Yet, their daughter had posted a series of allegations on social media, which were "already proven to have been unfounded", Justice Phang said. In her posts, the daughter named her father, and accused him of being a "mega pervert" who had affairs and sexually groomed his children.

The girl also gave an interview to an online news outlet, after its reporter came across her social media posts.

Justice Ong found that the woman had intentionally breached the court orders not to disclose to the children information relating to the case in court.

The woman appealed against the decision.

In his grounds of decision, Judge Phang said: "Having considered the facts and the evidence as a whole, we found that the appellant had deliberately acted in order to prejudice and harm the husband's reputation, as well as to drive a wedge in the relationship between him and the children."

He noted that the mother was previously fined for contempt of court, after refusing to hand the children over to their father for him to spend time with them as directed by the court. But she refused to pay the $3,000 fine and the court ordered that the sum be taken out of her share of the matrimonial assets.

The woman's lawyers for the appeal were Mr Ushan Premaratne and Mr Lim Toon Joo. The man was represented by Ms Luna Yap.

Mr Ushan told The Straits Times the mother is grateful for the court's show of judicial mercy and she is currently undergoing medical treatment.

Besides the $5,000 fine, the Court of Appeal also ordered the woman to pay her former husband $21,000 for the cost of the appeal.

Veteran family lawyers such as Ms Ellen Lee, with about 40 years of experience, and Mr Koh Tien Hua, a lawyer for more than 20 years, said that, as far as they know, this is the first divorce-related case where judicial mercy has been granted.

Mr Koh said the case is also significant, as it shows the emphasis the FJC places on therapeutic justice - a non-adversarial process that seeks to solve problems and help parents learn how to manage conflicts and engage in co-parenting, among other things.

He added: "This case reminds parents that they have to co-parent for the sake of the children and that the FJC frowns on efforts by one parent to alienate the children from the other parent."