National Anti-Corruption Commission boss Paul Brereton has hit back at his critics, saying there was a lot of misunderstanding about the watchdog’s role and warning many investigations would take years, not months, to conclude.

In a rare public appearance, Brereton told The Australian Financial Review Government Services Summit on Tuesday that only 10 per cent of the 5400 referrals to the NACC since it started in July 2023 met the legal threshold for further review, and only 1 per cent suggested serious or systemic corruption.