HONG KONG (AFP) - A Hong Kong couple left their Indonesian domestic helper without food or water after tying her to a chair and forcing her to wear a diaper while they went on five-day vacation, a report said on Saturday.

The pair, 42-year-old Tai Chi-wai and his 41-year-old wife Catherine Au were in court on Friday for "assault occasioning actual bodily harm" according to the city's official Judiciary website.

Tai and Au also face charges of false imprisonment, assault, and six counts of inflicting grievous body harm on their former maid Kartika Puspitasari over a period of two years ending last October, the South China Morning Post reported.

The court heard the couple, who deny the charges, would tie their maid up whenever they left their home or went to bed. It also heard that Au allegedly used a paper cutter on Puspitasari's hands and stomach and banged her head on a tap, the Post said.

The couple also allegedly beat her with a bicycle chain, a shoe and scorched her arms and face with an iron.

Puspitasari made her escape last October shortly after she was punished for eating chicken and a piece of cake from the couple's fridge after she was denied food for two days, the court heard.

To punish her, Tai allegedly slapped her face three times, tied up her arms and legs and pushed her into the bathroom before leaving the flat.

After realising the bathroom door was unlocked, Puspitasari crawled into the living room, loosened her ties and escaped to the streets where she sought help from a compatriot and was taken to the Indonesian consulate.

The Hong Kong Judiciary and the Indonesian consulate were not immediately available for comment when contacted by AFP.

The trial continues on Monday.

Hong Kong is home to nearly 300,000 maids from mainly south-east Asian countries, such as the Philippines and Indonesia.

A union representing domestic workers held a protest in March to call for an end to a policy which requires foreign maids to live with their employers, saying the rule exposes them to assault and sexual harassment.