The Australian Defence Force repeatedly offered to provide security for Victoria's quarantine hotels, contradicting claims from Premier Daniel Andrews.
Hundreds of defence force personnel were placed on standby across the country on March 27, after it was announced returned overseas travellers would be required to complete 14 days of hotel quarantine.
A federal government submission to Victoria's hotel quarantine inquiry on Tuesday said both NSW and Queensland accepted ADF support, taking on 360 and 100 members respectively.
In Victoria, private security were hired to guard the quarantine hotels.
The decision was made at a meeting chaired by Emergency Management Victoria Commissioner Andrew Crisp on March 27.
Recordings of the meeting were played to the inquiry on Tuesday.
"I suggest that at this stage we can manage this. The ADF will be just exactly what they are doing at the moment, helping us to plan for this particular operation," Mr Crisp said in the recording.
"At this stage we don't see a need for boots on the ground, so to speak."
He reiterated the decision in another meeting on March 28, following reports ADF personnel were patrolling quarantine hotels in NSW.
"I've said it before but I'll say it again, at this particular point in time we certainly don't see the need for ADF boots on the ground," Mr Crisp said.
Returned travellers began arriving in Victoria the following day.
Mr Crisp told the inquiry it was Victoria Police Chief Commissioner Graham Ashton's preference to use private security guards and he wasn't opposed.
"I've worked with a lot of private security and my thinking was, well-trained, well-supervised private security in this type of role would have been sufficient and effective," Mr Crisp said.
In his statement tendered to the inquiry, Mr Crisp said he was aware of "challenges" with security staff as early as March 30.
During a meeting on April 4, he learnt there had been reports security guards were "not following good social distancing practices and that a few breaches involving physical distancing and infection control practices".
On April 8, Department of Prime Minister and Cabinet secretary Philip Gaetjens emailed his Victorian counterpart Chris Eccles to again offer ADF assistance.
Referencing how the ADF assisted with security in NSW, Mr Gaetjens wrote: "I am sure the Commonwealth would be willing to assist Victoria in a similar way if you wanted to reconsider your operating model".
Mr Eccles replied: "Thanks Phil".
By mid-May, an outbreak emerged among hotel staff and security guards at the Rydges on Swanston hotel.
Another outbreak occurred at the Stamford Plaza in early June.
About 99 per cent of Victoria's second COVID-19 wave, which has killed hundreds and led to the nation's toughest lockdown, can be traced to the outbreaks.
It wasn't until June 24 that Mr Crisp made a request for 850 defence personnel to replace private security.
The request was rescinded a day later after the Department of Justice and Community Safety took over the program.
The federal government's submission also revealed Prime Minister Scott Morrison wrote to the premier three times, on July 4, 6 and 11, "reaffirming the Commonwealth's willingness to provide ADF support if needed".
Mr Andrews has repeatedly maintained the ADF never offered security for the quarantine hotels.
"(It's) fundamentally incorrect to assert that there were hundreds of ADF staff on offer and somehow, someone said no," he told a parliamentary committee in August.
The premier told reporters on Tuesday he wasn't interested in "having a debate with the prime minister".
"The prime minister's representations to the inquiry - I'll leave that to the inquiry to make recommendations and findings about that," he said.
Chief Health Officer Brett Sutton, his deputy Annaliese van Diemen and their Department of Health and Human Services colleagues Jason Helps and Andrea Spiteri will give evidence when public hearings continue on Wednesday.