Chief Health Officer Brett Sutton said it was “conceivable” all 1612 active COVID-19 cases in the state were linked to the program.

“It’s genomically linked to the (hotel) quarantine cases, but not all of the viruses that are out there at the moment are sampled, not all of them can be grown in order to get the genomic sequencing,” he told ABC Melbourne’s Drive program on Monday evening.

When asked if most cases could stem from one hotel, Sutton said “that’s conceivable absolutely”.

He said he used “pretty colourful language” when the genomic link was first made between hotel quarantine and outbreaks in the city’s inner north and west.

“They were actually doing a fantastic job managing all of the logistic complexities of it. But it speaks to the dangers of any positive case out there and the ability for it to spread very extensively as has occurred.”

Victoria has recorded 270 new coronavirus cases overnight, and Premier Daniel Andrews confirmed on Tuesday 28 of the cases were linked to known outbreaks, while 242 remain under investigation.

The state now has a total of 4224 cases, of which 1803 remain active.

Andrews announced an inquiry into the state’s quarantine scheme, to be led by former judge Jennifer Coate, after protocol breaches by guards at the Rydges on Swanston and Stamford Plaza hotels were identified as the source of coronavirus outbreaks.

According to The Age, a senior bureaucrat raised concerns about the program within 24 hours of its launch on March 28.

“We request that Victoria Police is present 24/7 at each hotel starting from this evening. We ask that DHHS urgently make that request as the control agency,” the email read.

In other states, police rather than security manage the quarantine of returned overseas travellers.

Meanwhile, outbreaks in aged care facilities have increased concern for elderly Victorians who are more likely to die from the disease.

The infection at Menarock Life residence in Essendon has spread to 26 staff and residents, becoming the largest aged-care cluster of coronavirus in Victoria to date.

An outbreak at Glendale Aged Care in Werribee has grown to 13 cases, while Japara Central Park Aged Care in Windsor has two positive cases.

A number of health care workers have also tested positive to the virus, prompting the Royal Melbourne Hospital to ban visitors from Tuesday.

Visitors will not be permitted at any of the hospital’s sites except if required as an essential caregiver.

-AAP, Benita Kolovos