There was a five day delay between the first case of coronavirus being identified at St Basil's aged care facility in Fawkner and the federal government being notified.
Almost 140 cases of coronavirus have been linked to the facility, and it is reported 20 residents at the facility have died from the disease.
A Senate committee examining the Australian response to the pandemic heard the first case in the facility was identified on July 9, but the Victorian Department of Health and Human Services didn't notify the federal government, which is responsible for the sector, until July 14.
Health Secretary Brendan Murphy told senators he believed the lack of notification is because the Victorian health authorities were under so much pressure due to the rising number of cases in the state at the time.
"I don't think they were aware it was an aged care outbreak until the 14th," Professor Murphy said.
The committee heard the facility's chairman was aware of the case on July 9, but the federal government was not informed.
"In this case the Victorians might have been under a lot of pressure but the service didn't notify us," said Michael Lye, the Health Department's deputy secretary of Ageing and Aged Care.
Evidence given to the committee showed the difficulty faced by the replacement workforce that entered the facility after all staff were forced to isolate after being considered close contacts of someone with the virus.
Aged Care Minister Richard Colbeck and Professor Murphy told the committee a scenario where all staff at a facility, including care and administration staff, needed to be isolated hadn't been considered because it was seen to be extremely unlikely.
In the first 48 hours when replacement staff took over St Basil's, Senator Colbeck said providing care was made more difficult because residents weren't in their normal rooms because of virus containment measures, as well as resourcing issues.
Families have reported their loved ones were neglected when the centre was taken over, and were dehydrated, not fed and in soiled clothing when transported to hospital.
The situation at St Basil's was also complicated due to the cultural and linguistic diversity of the residents, with the replacement staff not able to speak Greek to communicate with them.
"Clearly some of the residents didn't get the care they should have received as part of that process," he said.
"There's no point in me pretending it all went as it should have gone."
Professor Murphy said workforce shortages were a major factor in the aged care crisis in Victoria, where more than a thousand aged care workers are in self isolation or quarantine, and more than a thousand health workers in the same position.
The situation has been further complicated by the scale of the problem in Victoria, where the huge number of cases has led to delays in contact tracing and isolating contacts of cases.
Victoria recorded another 11 deaths from coronavirus on Tuesday, including a women in her 100s. All the deaths were linked to aged care facilities.
Ninety-seven residential aged care facilities in the state have recorded cases of the virus, but the committee was told only about 20 per cent of facilities had sever outbreaks.
More than a thousand cases of the virus in that state are linked to aged care, including 657 residents and 594 staff members. Almost 400 residents have been transferred to hospital, the committee heard, with more transfers continuing.