Foreign maids, cleaners and other domestic workers are being subjected to slave-like labour conditions in Qatar, with many complaining they have been deprived of passports, wages, days off, holidays and freedom to move jobs, a Guardian investigation can reveal.

Hundreds of Filipino maids have fled to their embassy in recent months because conditions are so harsh. Many complain of physical and sexual abuse, harassment, long periods without pay and the confiscation of mobile phones.

The exploitation raises further concerns about labour practices in Qatar in advance of the World Cup, after Guardian reports about the treatment of construction workers. The maids are not directly connected to Qatar's preparations for the football tournament, but domestic workers will play a big role in staffing the hotels, stadiums and other infrastructure that will underpin the 2022 tournament.

Our investigation reveals:

• The Philippine Overseas Labour Office (POLO) sheltered more than 600 runaway maids in the first six months of 2013 alone.

• Some workers say they have not been paid for months.

• Many housemaids do not get days off.

• Some contracts and job descriptions are changed once the workers arrive in Qatar.

• Women who report a sexual assault can be charged with illicit relations.

The non-payment of wages, confiscation of documents and inability of workers to leave their employer constitute forced labour under UN rules. According to the International Labour Organisation, forced labour is "all work which is exacted from someone under the menace of any penalty and for which the said person has not offered himself voluntarily".

Lack of consent can include induced indebtedness and deception about the type and terms of work, withholding or non-payment of wages and the retention of identity documents. Initial consent may be considered irrelevant when deception or fraud has been used to obtain it.

"Menace of penalty" can include physical violence, deprivation of food and shelter, non-payment of wages, the inability to repay a loan, exclusion from future employment and removal of rights and privileges.

Modern-day slavery is estimated to affect up to 21 million people across the globe.

When the Guardian visited in January, at least 35 runaway maids had sought sanctuary at the POLO in the capital, Doha, which provides support to 200,000 Filipinos in Qatar. The welfare officer said most complained of pay being withheld, insufficient food, overwork and maltreatment. Some said they had endured verbal and physical abuse by sponsors of different nationalities.

Eight Filipino workers interviewed by the Guardian said they had not been paid for six months, were sometimes deprived of food while cleaning for long hours and had had their passports confiscated.

"We are afraid," said 28-year-old Jane*. "We don't really know what to do. We are trying to survive. That's why we do part-time jobs secretly." If they are caught breaching their contract, the maids face months in a deportation centre. The repatriation process is often delayed when people do not have their passports, according to James Lynch, Amnesty International's researcher on Gulf migrants' rights.

Qatar vigorously denies it is a "slave state" and is understood to be reviewing the controversial system that governs migrant labour, and to have stepped up inspections of businesses that use migrant labour. The Qatari labour ministry said in a statement: "We have clear laws and contractual terms in place to protect all people who live and work in Qatar and anyone found to have broken those laws will be prosecuted accordingly." It said that non-payment of wages and confiscation of passports were illegal in Qatar, and added: "The vast majority of workers in Qatar – domestic or otherwise – work amicably, save money and send this home to improve the economic situation of their families and communities in their home countries."

But the Philippines-based OFW (Overseas Foreign Workers) Watch, which supports Filipino migrant workers, said physical abuse, delayed and refused salaries, the misrepresentation of employers and contracts and passport confiscations were common issues in Qatar. The Guardian has already highlighted this malpractice in its investigation into the mistreatment of migrant workers as Qatar gears up for the 2022 World Cup.

As with the construction workers, the abuse of maids is systemic and brought into sharp focus by a lack of legal protection and the kafala sponsorship system, under which workers cannot leave the country or change jobs without their employer's permission, Lynch said.

"The women we've spoken to who have suffered abuses in the workplace, ranging from excessive working hours to physical violence, their employers came from a variety of countries," he added.

Many maids say they do not get any rest days and that employers confiscate their mobile phones.

Several recruitment agencies contacted by phone told a Guardian reporter pretending to be a would-be client that they routinely withheld the passports of their migrant workers. One agency volunteered that it was up to the sponsor whether the maid had a day off. "If you want to give an off day, let them rest at your house," an Al Hadeel Manpower representative said. "Don't give them free days outside because there is more problems outside."

Domestic workers are not covered by Qatar's labour laws and cannot challenge their contracts in court.

François Crépeau, the UN special rapporteur on the human rights of migrants, said he was told during his eight-day visit to Doha in November that if some sponsors disliked the maid, they could have her arrested for theft. "These are all hearsay stories, but it was quite frequent," he said.

Crépeau, who will present a report of his Qatar trip to the UN in June, said he saw about 100 maids at the Philippine labour office waiting to be moved to the deportation centre, which housed about 1,300 people when he visited. He also visited the Central Prison, where he found women imprisoned with their babies as they served one-year sentences for adultery because they were unmarried.

Sharan Burrow, the general secretary of the International Trade Union Confederation, said some imprisoned babies were conceived when their mothers were raped by their employers.

The penalty for rape in Qatar is life imprisonment and, under some circumstances, death. Sexual harassment is illegal, but women who report such cases risk being charged with having illicit relations.

"They've become enslaved in Qatar, forced into abusive relationships, often become pregnant as a result of forced sexual relationships or rape and then the perpetrator has total power and refuses to sign an exit visa, so they end up imprisoned," Burrow said.

Crescente Relacion, the Philippine ambassador to Qatar, who declined to be interviewed but issued a written response to Guardian questions, said the embassy had assisted the fewer than five expatriates who had filed such charges with police in 2013. "Some victims have decided to settle amicably or not to file charges as doing so would significantly delay the repatriation," he said.

Case study



One runaway maid, Vanessa, fled to the Philippine women's shelter with only the clothes she was wearing because she said her employers of four years had cancelled her flight back home and confiscated her belongings for shouting at their children.

Vanessa said she had not had a day off in four years, but she did not regard playing with the children as work. She alleges the Indian mother of the family that employed her struck her because she did not want Vanessa to feed her infant son. "She hit my face because, yes, I admit that it's my fault because I fed the baby," she said. "What I didn't accept is that they took everything."

Among the items were precious photographs of her 10-year-old daughter, whom she has seen once during her only holiday, when she visited her mother in the Philippines in 2011, her mobile phone and 42,500 pesos (£580), she said. "Maybe they're telling to the police that I steal, but only God knows."

Because of the kafala system, Vanessa could not simply turn her back on her job or seek alternative employment. She is tethered to the employer via the sponsor who supports her migrant status in Qatar. She was faced with an unpleasant choice: tolerate the abuse or run away.

*Names withheld to protect identities