The following cannot be taken as security for a loan:
It is illegal for anybody except the domestic worker or the relevant authorities to keep her passport, whether as collateral for a loan or otherwise. Note that most licensed money lenders will not retain original passports (though they might ask for a passport copy). Rather, it is often unlicensed money lenders or individual lenders who will retain domestic workers’ passports.
If your helper has given any of these items as security/collateral, encourage your helper to call and ask the money lender for them back immediately. If your helper prefers and if you are comfortable, you could call the money lender yourself (to ensure they take it seriously). If they refuse, contact the Hong Kong Police (999) and your helper’s consulate as soon as possible.