By Dominic Giannini in Canberra

The head of the national anti-corruption commission is under investigation for possible misconduct.

Commissioner Paul Brereton is under scrutiny following referrals about potential conflicts of interest due to his employment with Defence, and his continued involvement with the department’s watchdog.

“To date, I have been making inquiries about these two matters,” Inspector of the National Anti-Corruption Commission Gail Furness said in a February 6 letter to a parliamentary committee overseeing the commission.

“Now having sought and received material from the NACC, I have decided that that information warrants an agency maladministration or officer misconduct investigation.”

Mr Brereton has been under fire for failing to initially disclose he was still engaged with the Inspector General of the Australian Defence Force on a casual basis after becoming the commissioner.

The major general admitted he consulted with the IGADF on his inquiry into potential Australian war crimes in Afghanistan about 22 times since 2023, when he last fronted a parliamentary hearing in December.

His report found credible evidence of potential war crimes involving the killing of 39 Afghans between 2005 and 2016, and he has argued he only provided “very modest, informal assistance” without pay on the matter, which he was an expert in.

He argued he told the then attorney-general he intended to continue to provide advice to the IGADF when he was first appointed due to his expertise in the area.

Mr Brereton has also recused himself from defence-related referrals to the anti-corruption commission to avoid any perceived conflicts of interest with his former employer, following public pressure.

In mid-December, Ms Furness revealed she had received almost 90 complaints about Mr Brereton’s potential conflicts of interest since July 1 – the start of the current reporting period.

At the time, she told the parliamentary inquiry she requested more information from the anti-corruption commission before making a determination on whether to launch an investigation.