Wiktionary
n. (context Australian New Zealand UK English) A body set up by law which is authorised to enforce legislation on behalf of the relevant country or state.
Wikipedia
A statutory authority is a body set up by law which is authorised to enact legislation on behalf of the relevant country or state. They are typically found in countries which are governed by a British style of parliamentary democracy such as the UK and British Commonwealth countries like Canada, Australia, New Zealand and India. They are also found in Israel and elsewhere. In Britain, many such bodies are termed QUANGOs because of their semi-autonomous nature.
Usage examples of "statutory authority".
He sometimes envied the FBI for its statutory authority to track down kidnappers.
He'd broken at least a dozen State Department regulations dealing with the filing of true copies, but a good defense attorney could argue that they were only regulations, without statutory authority from Congress, and that as the Secretary of State, his own department's regulations were subject to his own revision.