A secret report into Victoria's third Covid-19 lockdown has found the virus escaped from a quarantine hotel in February when an unmasked woman was swabbed in a open doorway.
The virus then started 'pooling outside the door' of the room where a 38-year-old man who was using a nebuliser was quarantining with his infant child and partner.
Victoria Health officials had previously claimed the virus escaped from his room - sparking a five-day 'circuit-breaker' lockdown to control the spread of the outbreak.
The virus escaped from the Holiday Inn hotel at Melbourne Airport in February when an unmasked woman was swabbed in a open doorway, a report has found. The hotel is pictured on April 8
The Covid-19 Quarantine Victoria Infection Prevention and Control report found though either the man with the nebuliser or his partner caught the virus when they stepped out of their room to collect a meal or leave rubbish.
The virus then spread further down the corridor to a food and beverage worker in a room next to the family, according to the review obtained by The Australian.
An officer who dealt with the family's entry and release from the quarantine hotel also contracted the virus.
The family tested positive on February 4 and the officer later tested positive to the virus after showing symptoms for the first time on February 7.
The report said CCTV footage and staff interviews meant the 'proposed working hypothesis' was that the unmasked woman was the source of the outbreak.
Chief Health Officer Brett Sutton said in February the use of the nebuliser - a device used to vaporise medicine so it can be inhaled - was believed to have spread the virus.
International travelers entering Melbourne's Intercontinental Hotel on April 8. Authorities had previously believed the source of the February outbreak was a man who was using a nebuliser (woman pictured is not the woman involved in the breach)
'We think the exposures are all to that event, the use of the nebuliser, which then meant the virus was carried out into the corridor and exposed the authorised officer, the food and beverage service worker and also the other resident,' he said.
The Victorian man who was carrying the nebuliser in February said the backlash to the outbreak mad him feel 'like a criminal'.
He said he had declared the device to authorities.
Chief Health Officer Brett Sutton said in February the use of the nebuliser was believed to be the source of the outbreak
'If I was told that I couldn’t use it, I never would have used it,' he told The Sydney Morning Herald.
'The way it has all come out in the news and through the government has made it sound like I was using it illegally or that I have snuck it in or something like that. It’s been very distressing.
'You are left feeling like a criminal or that you’ve done the wrong thing. That has been the hardest thing in all this.'