A leading psychologist on disaster and trauma is set to appear before Victoria's inquiry into its hotel quarantine program.
Robert Gordon, a consultant to the Victorian Department of Health and Human Services, will give evidence to the board of inquiry on Friday.
Dr Gordon has been working in the field of disaster recovery since Ash Wednesday in 1983 and has worked with people and communities after the Port Arthur massacre, the Bali bombings, Black Saturday and the Christchurch earthquake.
AAP understands he was not consulted on Victoria's hotel quarantine plans.
It comes after former Victoria Police chief commissioner Graham Ashton appeared at the inquiry on Thursday.
A text message exchange between Mr Ashton and Australian Federal Police Commissioner Reece Kershaw was shown to the inquiry, linking Premier Daniel Andrews' office to the decision to use private security guards.
"Mate. Question. Why wouldn't AFP Guard people At The hotel??," Mr Ashton wrote to Mr Kershaw on the afternoon of March 27.
Ten minutes later Mr Ashton sent a follow-up text message: "Mate. My advise (sic) is the ADF do passenger transfer and private security will be used."
"Ok that's new," Mr Kershaw replied.
"I think that's the deal set up by our DPC (Department of Premier and Cabinet). I understand NSW will be a different arrangement," Mr Ashton said.
The text messages were shown to Victoria's hotel quarantine inquiry on Thursday.
"I don't remember where I got that or who I got that from," Mr Ashton, who retired from the top job in June, told the inquiry.
In his written statement to the inquiry, Mr Ashton said he did not know whose idea it was to use private security guards, but it was not his.
He suggests it was Department of Premier and Cabinet secretary Chris Eccles who made the suggestion about 1.20pm on March 27, just minutes before his text message exchange with Mr Kershaw.
An email written by Deputy Commissioner Rick Nugent on March 28 was also shown to the inquiry, which links the Department of Premier and Cabinet to the plans.
"The CCP (Chief Commissioner of Police Graham Ashton) advised me ... that the agreed position at this stage is private security will be employed for this health intervention," Mr Nugent wrote.
"DPC (Department of Premier and Cabinet) also rang me about this late last night and confirmed that was the arrangement."
He said if any increased risks or issues were identified, the Australian Defence Force could be brought in.
The inquiry has heard security guards caught COVID-19 from returned travellers in hotel quarantine, leading to the state's second devastating wave of coronavirus.
Hundreds of Victorians have since died from the virus, thousands are out of work and millions remain under the nation's toughest lockdown.
Australian Associated Press