Female migrant workers in Singapore face what amounts to forced labour due to a lack of legal protection, US-based rights campaigners say.
Affluent Singaporeans often hire maids from abroad
Human Rights Watch (HRW) said domestic workers were overworked and frequently denied food, pay and social contact, as well as suffering physical abuse.
Singapore's government said the report "grossly exaggerates" the situation.
Maids working throughout South East Asia complain of abuse. HRW produced a similar report on Malaysia last year.
Some 150,000 women work as maids in Singapore, mainly from Indonesia, the Philippines and Sri Lanka.
The report paints a grim picture of young women trapped in apartment blocks, beaten, sometimes raped, killed or driven to suicide by their employers.
The authors of the report say they believe such abuse is widespread in Singapore. In the past six years, at least 147 domestic workers have died in the city state.
The rights group interviewed 90 people and conducted case studies to compile its 128-page report, Maid to Order - Ending abuses against migrant domestic workers in Singapore.
HRW argues that by excluding maids from its Employment Act, Singapore is failing to comply with international law.
"A system that excludes a class of workers from labour protections, leaving them to work for 16 hours a day, seven days a week, for pitifully low wages is one that demands serious and meaningful reform," it says.
But Singapore's government denied it was exploiting the maids.
"On their own accord, FDWs [foreign domestic workers] choose to work in Singapore because of better conditions here compared to their home and other countries.
"Contrary to HRW's report, the majority of FDWs enjoy meaningful and safe employment in Singapore. An independent poll by Singapore Press Holdings in Dec 2003, revealed that over 80% of FDWs were happy to work in Singapore," the Ministry of Manpower said on its website.
One domestic worker cited in the report complained of overwork.
"Sometimes employers want the maid to clean until 2200 or midnight and to start working again at 0600," she said.
Another maid told HRW: "Sometimes there was not enough food... They bought food from outside, but not for me. When angry, [the employer] would throw my food in the rubbish... I was very scared. My employer told me, 'Tomorrow you have a punishment, no eating.'"
Foreign and domestic workers in Singapore at present have no right to any time off. As of next year, employers will be obliged to give them one day off a month or financial compensation.
But the report says the women should be given the same rights as other workers in Singapore.
The authors say Singapore is by no means the worst offender in the region, but they argue that this tightly controlled city state could improve conditions very easily, giving many thousands of vulnerable women greater control over their lives.