Victoria has been given the best indication yet that its tough virus restrictions are working, with daily case numbers plummeting to their lowest level in a month on Tuesday.

Victoria reported 222 more COVID cases on Tuesday – the lowest since 217 on July 18.

Sadly, there were also another 17 fatalities, bringing the state’s toll to 351. Tuesday’s deaths were lower than Monday’s grim record of 25.

They were 10 men and five women aged from their 60s to their 90s.

In good news for Victorians, Premier Daniel Andrews confirmed the number of active cases in the state was continuing to fall. There were 7274 active cases on Tuesday, down from 7474 on Monday.

But Mr Andrews urged residents to keep getting tested, even as the numbers reduced.

“I don’t want a situation where we see numbers continue to fall but at the same time the total number of tests falling also because that will mean we don’t have confidence that we have an accurate picture of how much virus is in the community,” he said.

“We don’t want that to be an inhibitor in any way of moving to a new phase and a new set of rules.”

Also on Tuesday, the inquiry into the state’s bungled hotel quarantine scheme heard Victoria’s devastating outbreak could be traced back to just seven travellers.

Dr Charles Alpren, a Victorian health department epidemiologist, said 99 per cent of the state’s current cases originated in two Melbourne hotels – the Stamford Plaza and the Rydges on Swanston. It was likely 90 per cent came from the Rydges, he said.

In his statement to the inquiry, Dr Alpren said he was “very confident” in his findings.

He said the Rydges hotel outbreak started with a family of four who returned from overseas on May 9.

They were moved to the hotel on May 15 and all four tested positive to COVID-19 by May 18.

On May 25, three hotel staff members were diagnosed with COVID-19.

By mid-June, a total of 17 staff and their close contacts had tested positive.

The virus then made its way out into the community.

An epidemiologist has confirmed Victoria’s outbreaks started in two quarantine hotels.

Elsewhere, health experts have welcomed Victoria’s latest figures, which come as Melbourne nears the end of its second week of a six-week shutdown.

Tough virus measures – including a nightly curfew – have all but shut Melbourne down until at least September 13. There are slightly less strict measures for the rest of the state.

Kirby Institute biosecurity program head Raina MacIntyre said Tuesday’s drop was “really great to see”.

“I think the Victorian government has done a really good job under very, very difficult circumstances and clearly the epidemic there has peaked and the numbers are coming down,” Professor MacIntyre told ABC radio.

“Hopefully it will be a week or so before we see those numbers down to the double digits.”

But she said more needed to be done to prevent health workers from contracting the disease.

“It’s a really urgent issue that needs to be addressed. Health workers all over Australia are really distressed,” she said.

On Tuesday, there were 1036 active virus cases in Victorian healthcare workers.

Healthcare workers have fallen victim to the virus in worrying numbers.

Also on Tuesday, there were also promising figures in NSW, which had only three new coronavirus infections to confirm.

Two were locally acquired, but only one remains a mystery (the other is a returned traveller in hotel quarantine).

NSW Health said it had had 16 cases in the past four weeks where the origin could not be traced.

On Monday, NSW Premier Gladys Berejiklian said she remained more anxious than ever about the spread of infections where the source was a mystery.

“Melbourne didn’t get worse because of the number of cases they had,” she said.

“They had undetected community transmission, which then unknowingly got to a stage where it … formed a number of different clusters and we certainly don’t want that to happen here.”

The undetected spread of the virus in Sydney’s west and south-west remains of most concern to NSW health authorities.

Elsewhere, Western Australia had one more coronavirus case on Tuesday. Queensland reported none.