Where a statute provides a specific defence to a criminal charge, it is the duty of the presiding magistrate to ascertain whether that defence is available to an unrepresented accused person. A failure to explore a statutory defence with an unrepresented accused constitutes a serious miscarriage of justice and will result in a wrongful conviction. In maintenance cases under s 23(4) of the Maintenance Act, proof that failure to pay was due to lack of means (not caused by unwillingness to work, misconduct, or unreasonable debts) is a complete defence, and this must be properly explored with unrepresented accused persons before conviction.