Gulf states are failing to curb serious abuses of Sri Lankan migrant workers employed as maids in their countries, a Human Rights Watch report has said.
The US-based group says abuse of maids is rampant in the United Arab Emirates, Saudi Arabia, Kuwait and Lebanon.
Employers routinely confiscate domestic workers' passports and confine them to the workplace, the rights group says.
The UAE has denied the charges, saying Human Rights Watch has ignored its efforts to improve workers' conditions.
More than 660,000 Sri Lankan women work abroad as maids, nearly 90% of them in the Gulf countries.
The 131-page report - called Exported and Exposed - documents the serious abuses that domestic workers face at every step of the migration process.
"Governments in the Gulf expose Sri Lankan domestic workers to abuse by refusing to guarantee a weekly rest day, limits to the workday freedom of movement and other rights that most workers take for granted," said Jennifer Turner, a women's rights researcher at Human Rights Watch.
"Too many abusive employers and unscrupulous labour agents get away with exploiting these workers without any real punishment."
The report is based on 170 interviews with domestic workers, government officials, and labour recruiters conducted in Sri Lanka and in the Middle East.
"Domestic workers typically labour for 16 to 21 hours a day, without rest breaks or days off, for extremely low wages of 15 to 30 US cents per hour," the report says.
Some domestic workers told Human Rights Watch how they were subjected to forced confinement, food deprivation, physical and verbal abuse, forced labour, and sexual harassment and rape by their employers.
"The Gulf countries need to do a lot more to stop abuse of domestic workers," Ms Turner said.
"The governments of Saudi Arabia, Kuwait and the UAE should extend labour laws to domestic workers, ensure their complaints can be heard and reform immigration laws so that workers aren't tied to employers."
The rights group has also urged the Sri Lankan government to improve regulation and monitoring of recruitment agents, as well as services for abused workers in consulates abroad.
The UAE has dismissed the charges.
In response, it said Human Rights Watch has "once again chosen to ignore many of the positive steps adopted by the UAE in recent months to improve conditions for temporary foreign workers in the country".
Many of HRW's recommendations have already been met or are in progress, the UAE's state news agency WAM quoted Anwar Gargash, minister of state for Federal National Council affairs, as saying.
Migrant workers make up the largest net foreign exchange earner for Sri Lanka.
The country has a huge unemployment problem, and often cannot dictate terms to richer nations.