"Hong Kong has the legal and political means to put its commitment to the protection of domestic workers into practice," said Tim De Meyer, senior specialist on global labour standards and law with the International Labour Organisation's Bangkok office. The office covers East Asia, Southeast Asia and the Pacific.

"It would send a strong message from a developed economy that domestic work, when truly decent, is a professional job, and brings substantive economic and social benefits to the families of employers and workers, and their communities and societies."

The Asia-Pacific region employs more domestic workers than any other part of the world, with 21.5 million working in private homes. The number is up from 13.8 million in 1995, and most are girls or women.

Hong Kong's legal framework was "significantly stronger" than that in most places with a similar number of domestic workers, De Meyer said, but it could become a leader in the region by amending its labour laws.

"Allegations such as the ones made in the recent case of Erwiana are unfortunately not uncommon in the Asia-Pacific region - nor in the world as a whole for that matter," he said.

"Hong Kong has the choice to go through this process by itself - meaning in consultation with organisations representing domestic workers and their employers - or to ask the ILO for technical assistance."

If some conditions, such as access to legal protection and the live-in requirement - which could create an environment of abuse - were amended, the city could become a more attractive place for domestic workers.

In September, the ILO ratified its domestic workers convention, with 11 countries now signed up.

Uruguay and the Philippines joined first, with Bolivia, Ecuador, Germany, Guyana, Italy, Mauritius, Nicaragua, Paraguay and South Africa signing up later. Beijing and Hong Kong have not signed.

It is the first treaty that deals specifically with labour rights for domestic workers, an industry of at least 53 million worldwide, and covers issues such as days off, minimum wage and set hours.

Joseph Law Kwan-din, chairman of the city's Employers of Overseas Domestic Helpers Association, said that if the live-in requirement were lifted, it would cause havoc in the local property market.

"Hong Kong is already very short of living space, but if just 20 per cent of live-in maids - or 66,000 - were allowed to live outside, rents would rise immediately," he said.

Hong Kong has about 300,000 overseas maids, mostly from the Philippines and Indonesia, but also recently from Bangladesh and Myanmar.

Hard Labour: Domestic workers in Asia-Pacific

In Asia, four out of five domestic workers are women

Across the Asia-Pacific region, one out of 12 wage-earning women works in this sector

One per cent of maids in the Asia-Pacific are covered by laws that regulate working hours

Just 3 per cent are entitled to one day off a week and annual leave

Domestic workers typically earn less than half of what is considered an average wage; some earn no more than 20 per cent of that average

Globally, more than two out of every five workers do not get the minimum wage; in Asia, nearly nine in 10 are not entitled to this

Labour laws across Asia are less likely to address basic rights for overseas domestic workers; in some countries, six out of 10 are excluded from any legal protection

Source: United Nations’ International Labour Organisation