A civil liberties advocate says the criteria used to determine which offenders will be required to wear alcohol-detector bracelets needs to be clear.
Corrections Minister Anne Tolley says if changes to legislation are adopted by Parliament, high-risk offenders and people on bail will be fitted with the ankle bracelets that can detect the presence of alcohol through the skin.
Auckland Council for Civil Liberties president Barry Wilson says the definition of high risk must be spelt out clearly, otherwise the bracelets could be used for just about anyone.
Mrs Tolley says offenders who have committed violent crimes under the influence of alcohol would be considered high risk.
She says if alcohol is detected, offenders will be arrested or charges will be laid in court.