A Singaporean couple were convicted on Wednesday of violating employment laws for starving their Philippine maid until her weight dropped to 29 kilograms (64 pounds).

Trader Lim Choon Hong and his wife, Chong Sui Foon, both 47, admitted failing to provide enough food for a foreign domestic worker over a 15-month period.

They will be sentenced at a later date. The offence is punishable by up to a year in jail plus a maximum fine of Sg$10,000 ($7,300).

A district court heard that Thelma Oyasan Gawidan, 40, lost nearly 20 kg, shed hair and stopped menstruating while working for the couple at their condominium in the posh Orchard Road area.

Gawidan was only allowed two meals a day, usually a few slices of white bread and small portions of instant noodles prepared by Chong.

Even when Gawidan went with the family on a Hong Kong holiday, Chong made sure to pack white bread and instant noodles for her maid.

Gawidan had no access to her mobile phone and was not allowed to go out on her own to buy food, court papers showed.

About a year into her employment, she was made to use a bathroom next to the condominium's swimming pool whenever she had to relieve herself or take a shower, and had to be accompanied by a family member. She was only allowed to shower twice a week.

Gawidan ran away in April 2014 and called a compatriot for help.

She was taken to a migrant worker shelter which helped her file a complaint with the manpower ministry.

Many Singapore households depend on foreign domestic help. In 2015 there were 231,500 foreign maids working in the affluent city-state, mostly from Indonesia and the Philippines.

Lim and Chong will appear before the court again on April 22 after a psychiatric assessment of them is completed.