Abu Dhabi royals in Belgium slavery case

Princess Hamda Alnehayan, the widow of the sheikh of Abu Dhabi, and her seven daughters are accused of confiscating the passports of their employees, and refusing to pay their salaries.A court case involving eight members of the Abu Dhabi royal household who are accused of treating 20 domestic workers like "slaves" has got under way in Brussels.

The princesses are facing charges of human trafficking, deprivation of liberty and treating their employees in an "inhumane and degrading" way.

Lawyers said that the domestic workers, who had been hired as nannies, cooks and domestic helpers, had to be at the princesses' disposal day and night, and were never allowed to leave the property.

The lawyers also said the princesses had insulted their workers, by calling them "cows, dogs and whores," and made them sleep on mattresses outside the princesses' bedrooms.

The alleged victims' lawyers are calling for damages of 2500 euros ($A3690) per worker, plus a six-figure sum in compensation for unpaid salaries as well as overtime, night and weekend pay in accordance with Belgian labour law.

The case dates back to 2008. Following a tip-off, Belgian police had raided a luxury hotel, where the princesses occupied an entire floor for a whole year.

The Belgian Federal Centre for Migration is a co-plaintiff in the case. The domestic workers are reportedly from the Philippines, Morocco, India, Egypt, Turkey, Iraq and Syria, and were allegedly held captive for eight months.