HONG KONG (AFP) - Hong Kong on Friday vowed to strengthen legal oversight over maid employment agencies following a spate of abuse cases that have caused widespread shock and anger.

City authorities said they would step up surveillance against unscrupulous agencies and look into increasing penalties against those who take advantage of maids.

The announcement came as a new case of domestic helper abuse was reported in the local media.

A 28-year-old Indonesian maid allegedly had her finger sliced off by her employer after failing to understand something her boss had said, local television network RTHK reported on Friday.

Earlier this year the alleged torture of an Indonesian maid by her Hong Kong employer caused uproar, with thousands of maids taking to the streets to demand justice in January.

Images of the injuries sustained by Ms Erwiana Sulistyaningsih, 22, who was reportedly left unable to walk following eight months of abuse, shocked the southern Chinese city but campaigners warned such assaults were merely the tip of the iceberg.

A spokeman for the labour department said it would step up surveillance on agencies and show offenders that the government is serious about the issue.

"The Hong Kong government would tackle the issue in a holistic and multi-pronged manner with various short, medium and long-term measures," she told AFP.

The spokesman added that the city's labour minister "would not rule out any possibility at this juncture, including the possibility of increasing the penalty" for unscrupulous employment agencies.

While campaigners have called for tougher measures against local agencies, city officials say there is little they can do to stop overseas agencies from taking advantage of maids, many of whom pay large fees to find work in Hong Kong.

Among the policies set out, retired police officers will conduct inspections at maid agencies, the South China Morning Post reported.

But the government has insisted on keeping both the two-week and live-in rules, which are extremely unpopular with domestic helpers.

Foreign maids are required by law to live with their employers and also need to leave the city within two weeks after their employment has ended.

Campaigners say the laws leave maids vulnerable to abuse and with little ability to change employers.

"They still insist on policies being questioned...there is no serious policy reform," Ms Eman Villanueva told AFP.

Foreign domestic helpers in Hong Kong by law must be paid at least HK$4,010 (S$654) a month and are entitled to free food and accommodation, and receive statutory holidays.

The semi-autonomous Chinese city is home to nearly 300,000 maids from mainly South-east Asian countries - predominantly Indonesia and the Philippines - and criticism from rights groups over their treatment is growing.

Amnesty International in November condemned the "slavery-like" conditions faced by thousands of Indonesian women who work in the Asian financial hub as domestic staff and accused authorities of "inexcusable" inaction.

It found that Indonesians were exploited by recruitment and placement agencies who seize their documents and charge them excessive fees, with false promises of high salaries and good working conditions.