A Hong Kong woman was given a six-year prison term on Friday for abusing her Indonesian maid in a case that aroused widespread outrage over its brutality.

Law Wan-tung was sentenced after her conviction earlier this month on eight charges of assault, grievous bodily harm and criminal intimidation against 24-year-old Erwiana Sulistyaningsih in a case that highlighted the vulnerabilities of migrants working as domestic staff across Asia and the Middle East.

Law, 45, displayed no reaction as the sentence was handed down by district court judge Amanda Woodcock, who said: “The seriousness of the charges and circumstances of the offences means a lengthy prison time is appropriate.”

Erwiana Sulistyaningsih (right) is greeted by her supporters outside the district court in Hong Kong. Photograph: Tyrone Siu/Reuters

The judge fined Law HK$15,000 ($1,930) for 10 charges of failing to pay wages or grant time off. She had earlier pleaded guilty to one other charge of failing to buy insurance.

Sulistyaningsih’s case came to light when graphic pictures of her injuries started circulating among Indonesians in Hong Kong, showing her face, hands and legs covered with scabs and lacerations, and blackened, peeling skin around her feet.

“I am so happy because finally my employer is in prison, although only for six years. But for me, finally justice is delivered,” Sulistyaningsih, through an interpreter, told reporters outside court.

Sulistyaningsih worked for Law, who has two teenage children, for about eight months starting in June 2013.

About half of Hong Kong’s 330,000 foreign domestic helpers come from Indonesia, almost all of them female and earning a minimum wage of about $500 a month.

Court heard that Sulistyaningsih suffered broken teeth, scratches all over body and blows to her head at the hands of Law, who also jammed a metal vacuum cleaner tube into her mouth, causing her lip to bleed. On one occasion, Law also forced Sulistyaningsih to stand naked in the bathroom during winter while she splashed water on her and pointed a fan at her.

Woodcock said Law showed a lack of compassion and her “contempt was reserved for those she saw as beneath her”.

Sulistyaningsih was given little rest or food and at one point was so hungry that she knocked on the next-door neighbour’s door at 2am to beg for something to eat.

When her injuries became so severe she was unable to work, Law attempted to send her home to Indonesia with just HK$70 ($9). Law escorted Sulistyaningsih to the airport, put makeup on her injuries, made her wear an adult diaper and threatened to hurt her family in order to reduce the risk she would get caught.

Her case only came to light when a fellow Indonesian at the airport noticed her.

The judged criticised Hong Kong government rules requiring maids to live with their employers, which she said contributed to the abuse cases that often end up in courts. She urged the Hong Kong and Indonesian governments to investigate the practice of employment agencies charging would-be migrant workers high fees for jobs overseas, which often saddles them with big debts they have to work off.