Ms Williams said the outbreaks were traced back to seven people in three rooms.

‘‘So in fact, 96.8 per cent of the people in quarantine did not go on to spread the virus,’’ Ms Williams said.

The department introduced testing of detainees on day three and day 11 of their two-week quarantine in the hotels.

‘‘I’m not saying we would have just let people out,’’ Ms Williams said.

‘‘The major risk of identifying people occurred in that first week ... so it may have been possible to detain people for a shorter period and then self-isolate.’’

But in the first wave of cases, a large number of people who came from overseas weren’t self-isolating and passed the virus on, Ms Williams said.

'Would you work there?'

Public health experts have said there was a "high risk" of surface transmission inside the hotel following the outbreaks in late May with problems with the cleaning regime and use of personal protective equipment, particularly by the security guards contracted to work there.

"If you knew those things, is that a place you would be prepared to work?" Counsel assisting the inquiry Ben Ihle asked Ms Williams.

Ms Williams paused, then said: "I was, I did go down to those hotels. I did observe that staff who practiced the processes that we proposed, social distancing, proper use of PPE and hand washing, did not become positive and a range of things were in place at that hotel."

Mr Ihle asked her if it was a safe place to work.

"There were a number of things that were done to ensure staff were as safe as they could possibly be," Ms Williams replied.

"Is it possible with COVID in the environment to be 100 per cent safe? No, and our experience in the hospital system at the moment indicates that."

Guests were 'by and large compliant'

More than 20,000 people went through the quarantine program from the end of March until it was suspended in June due to the outbreaks within the program.

Ms Williams said she had a ‘‘lot of respect’’ for those who were detained in hotel quarantine.

‘‘It was boring, it was hard to deal with if you had a family ... They were doing that because they understood what the risks were,’’ she said.

Ms Williams said the guests were "by and large very compliant" but it became very difficult to manage the health and wellbeingof some of them.

"We were balancing a public health risk ... to contain the virus with the pressure to provide people with fresh air, to enable people to have compassionate leave."

Other states, Ms Williams said, were "less inclined" to let people leave their rooms, but Victoria's response had to be balanced against the state's charter of human rights.

She said program decision-makers were "put under pressure" to accommodate fresh air breaks from the guests.

"There were many issues that guests had. Initially there was quite a focus on food, so people were often unhappy with the choice and the nature of the food provided," she said.

Some also had mental health problems and were heavy smokers, in distress being in rooms without windows that opened.

Cleaners in the dark on 'hot' hotel

The inquiry was earlier told that cleaners weren’t told they were being sent to a "hot" hotel after a COVID-19 outbreak.

The cleaners, from Ikon Services Australia, had been contracted by the Department of Jobs, Precincts and Regions to perform deep cleans of hotel rooms in the program.

They were contracted to clean rooms at the Rydges on Swanston, a "hot" hotel that housed returned travellers with COVID-19.

But cleaners weren’t told the hotel was a designated COVID hotel, the inquiry heard.

The Rydges on Swanston became the site of major outbreaks between workers at the hotel, which health experts say is responsible for 90 per cent of current cases in Victoria.

‘‘Were you told Rydges was designated a COVID hotel?’’ counsel assisting the inquiry, Ben Ihle, asked.

‘‘No we weren’t. We weren’t informed,’’ Ikon Services’ general manager Michael Girgis replied.

This is significant as the process the cleaners would go through to put on and take off their personal protective equipment may have changed if they had of known. Their process was donning and doffing full PPE inside the hotel in a designated room, rather than outside of it, before they entered the rooms.

Ikon was called in to clean common areas on May 28 after a staff member at the hotel tested positive to COVID-19 on May 26.

But Mr Girgis said he only found out why they had been asked to clean common areas when they contacted the hotel.

‘‘That was the only way we found, just by chance that morning, by asking the question,’’ Mr Girgis said.

Ikon was called back to clean the hotel on June 3 and 4. By that time, the hotel had been shut down to new arrivals after more workers tested positive. Not that Mr Girgis was told, he said.

‘‘No we weren’t made aware of that as well,’’ he said.

Health department medical advisors ordered a deep clean of common areas after the first positive test on May 26, which Ikon was contracted to do.

But, the inquiry heard previously, the deep clean was inadequate with a wrong disinfectant used.
Mr Girgis said he was never told their cleaning wasn’t up to scratch.

Mr Girgis was also shown photos taken by prominent human rights lawyer Hugh De Kretser, who was quarantined in the Rydges in late June when it was reopened to new arrivals after it was shut down from early June after the outbreaks.

The photos showed used face masks and plastic gloves under the bed, food crumbs on the floor and stains on the doonas.

The room had not been used since it was cleaned in early June.

‘‘This is not indicative of the work we produce,’’ Mr Girgis said, at a loss to explain why the room was in such a state.

Mr Girgis’ lawyer said in the swabs of more than 1000 rooms Ikon had cleaned had always come back negative for COVID-19.