HONG KONG (AFP) - A Hong Kong woman who allegedly tortured her Indonesian domestic helper in a case that sparked international concern is facing new charges relating to unpaid wages and owed holidays, a court heard on Tuesday.

Law Wan-tung, a 44-year-old mother-of-two, was arrested in January for seriously wounding Erwiana Sulistyaningsih, her former domestic helper.

Ms Sulistyaningsih said she suffered months of severe abuse in a high-profile case which has renewed worries over the treatment of domestic helpers in the southern Chinese city and sparked angry protests.

Time magazine on Friday named Ms Sulistyaningsih as one of the world's 100 most influential people, hailing her bravery in speaking out against her former employer.

Twenty-five new summonses were read out during a hearing on Tuesday at which a presiding magistrate agreed with prosecutors that the case should be transferred to a higher court.

The summonses referred to various periods when Law failed to grant Ms Sulistyaningsih a total of 16 days leave, as well as unpaid wages amounting to about HK$28,000 (S$4,540), a Department of Justice spokesman told AFP.

The case was adjourned until May 20. Law remained silent throughout except when she told the magistrate she understood the new charges.

She is accused of causing Ms Sulistyaningsih grievous bodily harm, and is also charged with assault causing actual bodily harm, common assault and four counts of criminal intimidation - charges related either to Ms Sulistyaningsih or to her treatment of her two previous Indonesian domestic helpers.

Prosecutors have said she turned household items such as a mop, a ruler and a clothes hanger into "weapons" against her maids.

After Ms Sulistyaningsih's ordeal was exposed, local migrant groups held protests calling for justice for abused maids.