Government Services Minister Danny Pearson on Wednesday confirmed Matiu Bush, general manager of infection prevention and control at COVID-19 Quarantine Victoria (CQV), had been stood down overnight pending a review.

Bush, who has been involved in the program since June, chooses to be identified as they/them.

They are one of 15 CQV leaders approved to work across a number of the state's hotel quarantine sites.

According to reports published in The Australian on Wednesday, Bush had to be counselled for initially refusing to undergo a mandatory test after visiting one of the hotels.

"I'm the head of IPC and I override that protocol," they reportedly told an Australian Defence Force member working at the hotel.

Emma Cassar, head of CQV, said Bush was tested at another location on the same day.

Bush was also accused of breaching infection controls after visiting another quarantine hotel.

They reportedly left the hotel, which was not hosting returned travellers at the time, to get a coffee and returned without changing their mask or sanitising their hands.

"From an IPC perspective, the risk was minimal, if not zero," Ms Cassar said, though she conceded their behaviour was not befitting of a leader.

"I don't think the public would want to see someone in a senior leadership role continue to behave in this way," Mr Pearson added.

Other incidents reported by The Australian include contractors and bureaucrats being allowed to enter or trying to enter hotel sites in Melbourne despite not be being vaccinated, as is required.

While nearly all were told to leave once their vaccination status was known, in some cases it was not checked when they entered.

The incidents reportedly occurred at the Holiday Inn at Melbourne Airport, Novotel and IBIS at Melbourne Central, InterContinental Melbourne and Sheraton's Four Points Hotel.

The newspaper also published an internal report contradicting claims by the government that an outbreak at the Holiday Inn was caused by a banned nebuliser.

The outbreak sparked a five-day lockdown of the state in mid-February.

According to the leaked report, the "proposed working hypothesis" was that the leak was caused by a staff member who swabbed a woman in an open doorway inside the hotel. The virus then spread through the corridor.

Ms Cassar said that was incorrect.

"The working hypothesis is still, as I understand, that this was caused by the nebuliser," she said.

Acting Premier James Merlino told question time the incidents proved hotel quarantine was not a "fit for purpose model".

He has been lobbying the federal government to fund the construction of a purpose-built quarantine facility in Melbourne's north for returned overseas travellers.

Federal Health Minister Greg Hunt praised the state government for taking "swift action".

"We have confidence in the quarantine system right around the country. It's been 99.99 per cent effective in preventing breaches," he said.

The state's second wave, which last year resulted in more than 18,000 new infections, 800 deaths and an 112-day lockdown, leaked from hotel quarantine.

The program was overhauled after a judicial inquiry.

Opposition Leader Michael O'Brien said the government had failed to learn from its mistakes.

"Every single day we see new evidence that this government still hasn't got hotel quarantine right," he told reporters.

It comes as Victoria recorded its 68th consecutive day without a locally acquired case of COVID-19 on Wednesday. There were also no cases in hotel quarantine.

A record 8406 people were immunised at the state's vaccination hubs on Tuesday.

Australian Associated Press