Former Fairfield councillor Phuong Ngo is serving life at Goulburn Supermax prison for masterminding Newman's 1994 murder.

Solicitor for Ngo and former upper house MP, Peter Breen, told the inquiry Ms Meagher had confirmed her willingness to give evidence at the inquiry, but he had not asked her about the strength of the allegations.

The inquiry also heard from long time Ngo supporter Marion Le, who said former Fairfield councillor Albert Rance had confessed to single-handedly murdering Newman to her.

When Rance failed to ever repeat the confession Ms Le said she held doubts about his role.

The inquiry also heard Ngo is currently running a corrosion simulation on a similar weapon to the one found in the Georges River to establish if corrosion patterns could be consistent with the time of submersion.

At least three of the detectives on the Newman case were members of the Major Crime Squad North, which was found by the Police Integrity Commission to have dumped a cache of weapons used to set up criminals into the Hawkesbury River.

The inquiry continues.

- Jenna Daroczy