The monthly sum needed to maintain a law undergraduate has come under scrutiny in a divorced couple's court battle as a judge criticised claims for clothes, bags and pocket money as being too high.

At issue was how much the father should contribute to support his only daughter, a 20-year-old National University of Singapore (NUS) student who now lives with her mother.

The couple split 10 years ago and he has been paying $950 a month for his daughter's expenses since 2010.

But his former wife applied to court last year to increase the sum to $1,450, in addition to him paying all of their daughter's annual university fees.

District Judge Lo Wai Ping was not convinced and, in judgment grounds released yesterday, ordered the man's maintenance sum for his daughter to remain at $950 and reduced his contribution towards her $17,563 annual tertiary fees to a maximum of 75 per cent.

The judge noted that the father, who has since remarried, "has been struggling" since last October to pay his former wife $2,300 a month for their daughter, comprising $950 for living expenses and $1,350 for tertiary fees. He also pays his former wife $500 in monthly maintenance.

The judgment means he now pays a total of $2,550 to his former wife and their daughter - $250 less than he used to.

"The issue in this case is whether, having regard to all the circumstances of the case, the monthly sum of $950 is still reasonable... now that the (daughter) is 20 years old and a law student," said Judge Lo.

She explained that the sum had to be seen in the context of the entire increased maintenance ordered due to the daughter's change in circumstances from college student to undergraduate, which amounted to a monthly average of $2,050, including $1,100 per month in tertiary fees.

None of the parties involved in the case has been named.

The mother, defended by lawyer Mimi Oh, had tabled various items such as food, transport and other allowances, and claimed that her daughter's current living expenses had soared to $2,225 a month.

The father said the expenses were "inflated and unreasonable".

He said the $950, when added to the mother's contribution, was "more than sufficient" for their daughter to live comfortably as a university student.

His lawyer Lim Poh Choo supplied data on the monthly expenses that an undergraduate may incur at NUS, Singapore Management University and Nanyang Technological University. Ms Lim argued these figures showed an undergraduate would need about $750 in monthly living expenses.

The judge found that some of the monthly expenses claimed by the mother for her daughter "were indeed inflated and exaggerated".

Among other things, the mother explained that her daughter needed $200 a month for clothes, shoes and handbags as she was required to wear office attire when giving presentations in school and attending court.

"Even so, there is no necessity to buy a new set every month for such school presentations or court attendances," said the judge, ruling that $50 a month for these items would suffice for an undergraduate.

The judge also found that the $600 sought for personal allowances was "too high", given that all the daughter's expenses had been covered separately under other items. She halved the sum payable to $300 a month.

This $300 would also suffice to cover the miscellaneous expenses of $230 a month billed for items such as toiletries and presents, she ruled.

Judge Lo further noted that the research presented by the father included food prices at the NUS Bukit Timah campus, and accepted that prices at campus canteens would be cheaper, reducing the $600 a month sought for food to $350 a month.

The father is currently a sole breadwinner who sends $2,000 monthly to his China-based wife and six-year-old child, in addition to what he now pays for his daughter and former wife.

Judge Lo added that the working mother is also obliged to maintain her daughter and is able to do so, given her monthly income of about $3,000.

Underlining that both parents can provide reasonable maintenance only as best as they could, the judge said "the daughter is not precluded from taking on her own part-time work to earn some extra money to indulge in the luxuries she wants".