A competitor seems to have received inside information, what can I do?

This should be raised promptly and in writing with the agency's procurement lead, giving the reasons for your concerns and any evidence. Agencies must maintain the confidentiality of tenders and ensure a level playing field, and information provided to one supplier that is material to the tender should be provided to all. If there is evidence of collusion between bidders, such as price fixing or bid rigging, this can breach the Commerce Act 1986, and since 2021 cartel conduct, including bid rigging, can be a criminal offence. You can report suspected cartel behaviour to the Commerce Commission, which has an investigation and leniency system. Keep records of what you observed, and take legal advice before making formal allegations, since defamation risk arises if claims are made without evidence.