Lockdown restrictions will be eased in metropolitan Melbourne from 11.59pm tomorrow night, however a raft of restrictions will remain in place.

High testing numbers and very low coronavirus positivity rates mean the five reasons to leave home will be overturned, Acting Premier James Merlino said.

"The existing 10 kilometre limit will be increased to 25km," he said.

"That means the only reasons to go further than 25km will be for work, education, caregiving or getting a vaccination."

LIVE UPDATES: The latest on the Victorian lockdown lift

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Schools will be able to return to in-person learning, but office workers have been asked to remain at home if possible.

Melburnians will not be able to have visitors to their homes, but outdoor gatherings are allowed for up to 10 people.

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"Masks will no longer be required outdoors unless you cannot maintain a 1.5 metre distance, but it is important that everyone continues to wear them indoors, whether that is shopping, on the train or at work," Mr Merlino said.

"Funerals are limited to 50 people, weddings are limited to 10. Religious ceremonies will be capped at 50 people inside."

Offices will be allowed to open for up to a quarter of staff, but no more than ten people.

Retail can reopen with density limits of one person per four square metres, and community sport can return to training.

READ MORE: What's coming back and what's staying closed

Hospitality venues can open with seated service at a maximum patron cap of 100, including 50 people indoors.

Hairdressers and beauty salons can also resume for treatments where masks can be worn.

Community sport can return for training and auctions can occur outdoors, with a maximum of 50 people.

Venues in Melbourne such as gyms, amusement parks, dance studios and nightclubs will remain closed, Mr Merlino said. 

A further $8.36 million in funding has been announced to provide an additional $2000 grant to support thousands of businesses that will remain shut. 

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Mr Merlino described the easing of lockdown restrictions as a "good day". 

"This is a good day. Everyone should be absolutely proud of what we've all achieved together, but we know that this isn't over yet and until we have widespread vaccination across Victoria and across our country, the virus will still be with us," he said.

"So we cannot let complacency creep in."

Restriction changes for regional Victoria

Restrictions will further ease for regional Victoria from 11.59pm tomorrow. 

Household gatherings can occur with up to two adults per day, plus dependents. 

Public gatherings have been increased to 20 people. 

Restaurants and cafes can open to a maximum of 150 people for seated service, including up to 75 allowed indoors. 

Religious ceremonies will be capped at 150 people at the venue, with no more than 75 people allowed indoors. 

Funerals will be limited to 75 people, while weddings will be limited to 20. 

Offices will remain capped at 50 per cent of staff. 

Community sport can return for all age groups, both for training and for competition in regional Victoria. 

Visits to aged care homes will still not be allowed in both Melbourne and regional Victoria, despite restrictions easing.

Chief Health Officer Professor Brett Sutton said it was not possible to end the city's lockdown sooner. 

"We have needed the last few days to see that new cases are emerging in people already in quarantine, no new mystery cases emerging, the primary close contacts decreasing by hundreds as it has done each day and the number of exposure sites down to 160-odd," he said.

"These things give my team the confidence this is the appropriate time to make those changes. It is not a case of flipping a coin and hoping for the best."

Mandatory QR codes

The Victorian Government will move to make QR code check-ins compulsory across all workplaces with "very limited exemptions". 

Previously, the codes have only been mandatory for customer-facing businesses.

"But through this outbreak, we have seen a number of cases occur in office settings so we want to take the next step on this," Mr Merlino said.

"We will be looking to consult with industry over the next few days around implementation and we'll finalise the details next week ahead of the requirements coming into effect."

When will restrictions ease further?

Mr Merlino said restrictions would likely further ease across Melbourne and regional Victoria next Thursday night. 

The restrictions preventing travel between regional and Melbourne will likely be scrapped then. 

"The regional/metro divisions will come down and we'll be able to travel more freely around the state again," he said. 

"For Melbourne, we'll be looking to further ease restrictions on venues, community sport will be able to come back for competition, so again, this allows local sporting clubs to start planning for what the weekend after next looks like. 

"We want to see what more can be done to further ease restrictions safely on businesses without jeopardising the gains we have made and we'll be looking again to make some further changes for regional Victoria. 

"We'll continue to assess the data each day and provide more detail, more certainty as soon as we can."

Only one new case recorded

Today's one new locally acquired case was a close contact already in quarantine directly linked to the Stratton Finance workplace. 

"Like many of the cases we are currently managing, this person was quarantining securely during their entire infectious period," Health Minister Martin Foley said. 

AMA Vice President Dr Stephen Parnis said the lifting of restrictions had to be "gradual", claiming travel limits were not "unreasonable".

"We know that people get around the entire city very quickly here in Melbourne,' he said.

"The outbreaks in the latest clusters were all over the metropolitan area. So we've got to do it gradually.

"I think the lifting of lockdown in this way is not unreasonable. Just so long as we can do it as quickly as the numbers allow us."

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The Delta strain mystery

Health authorities are still trying to determine how a returned traveller's Delta strain of COVID-19 seeped out of Melbourne's quarantine system.

"The individual involved had exemplary behaviour from an infection prevention and control point of view coming off the plane and through the airport," Professor Sutton said.

"There has been some testing of the staff that was directly interacting and nothing has turned up. We will continue to look at that. The transport from the airport again, looks perfectly OK. But something has happened."

He said there were issues with ventilation and PPE that must be addressed. 

Whether home quarantine could become another alternative, Professor Sutton said that was a part of a "national conversation".

A 17-year-old has been charged with murder after an apprentice was allegedly attacked while trying to stop a fight at a 16th birthday in Melbourne's south-east earlier this year.

Police said Jason Langhans was attacked when he stepped in as a "peacemaker" as an altercation was escalating at the birthday with up to 100 guests in Tooradin in March.

He died three weeks later after his family made the "horrendous decision" to turn off his life support. Today, a 17-year-old was charged with his murder.

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Two other males also spoke to investigators and were released without charge.

The 17-year-old will appear in a children's court later today.

Heartbroken mother Carolyn Langhans struggled to hold back tears as she told reporters her "beautiful" boy had been ripped from their lives too soon.

"There is a big hole in our hearts," Mrs Langhans said.

"I'm devastated, my heart is broken. I've lost my son, he's not coming back."

The teenager was described as a "beautiful young man who had his whole life ahead of him".

The 17-year-old enjoyed fishing and playing footy for Narre Warren Football Club.

He was looking forward to completing an apprenticeship and had recently bought a four-wheel drive.

"He planned to get his licence on his 18th birthday," Mrs Langhans said.

"That's all gone now, that's been taken away from him.

"He is a loving, caring, gentle person. He wouldn't hurt a soul."

Tooradin is a semi-rural township on the outskirts of Melbourne, located about 57 kilometres south-east of the CBD.

Head and neck surgeons say more women are being diagnosed with mouth cancer and research is underway to help unravel what's fuelling the alarming trend.

"These mouth cancers historically occur in older men, particularly smokers and drinkers," said Associate Professor Carsten Palme, Director of Head and Neck Surgery at Chris O'Brien Lifehouse.

But surgeons here and overseas have identified a rise in the number of women being diagnosed with cases increasing about 5 per cent each year.

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Those women are not presenting with traditional risk factors and their diagnosis usually "comes out of the blue".

"A lot of research at the moment at our institutions is being done to try and identify exactly what is happening and why," Dr Palme said.

Dr Palme said his youngest patient had just finished her HSC.

"She was 18 she presented with an ulcer at the right side of her tongue which was initially thought to be a benign traumatic ulcer and she ended up having a stage three tongue cancer," he said.

"We are commonly seeing women between the ages of 20 and 40 present to our clinics, pretty well on a weekly basis," he said.

According to the Australian Institute of Health and Welfare, more than 5,000 Australians are diagnosed with head and neck cancers each year.

Doctors at Chris O'Brien Lifehouse are now routinely using innovative approaches to remove and rebuild a patient's jaw to help cure their cancer.

Tara Flannery, aged 49, was diagnosed with squamous cell cancer in her gum and doctors said removing the entire top jaw would give her the best chance of a cure.

On its own, the surgery would cause significant cosmetic deformities and would make eating, swallowing and speaking extremely difficult.

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The teacher feared she would have to stand up in front of 30 kids with a disfigured face.

"I didn't want to stop teaching," Ms Flannery said.

The Lifehouse team created a 3D model of Ms Flannery's jaw which enabled them to virtually map out her complex operation.

"It means what we plan on the computer can then be executed at surgery. And for something as complicated as the jaw, it's absolutely critical," said Dr David Leinkram, Lifehouse Oral and Maxillofacial Surgeon.

The doctors used the position of Tara's top and bottom teeth as a starting point for the reconstruction and worked backwards.

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"So we want to keep those teeth exactly where they were before and then we plan the reconstruction and the immediate dental implant at that time," Dr Palme said.

Six weeks before the major surgery, they placed titanium implants and skin grafts inside her calf bone called the fibula.

The skin grafts would form her new upper gum.

Three segments of that bone and nearby blood vessels would eventually be removed to build her new jaw.

During the pre-fabrication process in the leg, specialist dentists take a mould to help build a bridge for her new acrylic teeth.

"Tara is a phenomenal example of what we can achieve in this day and age," said Dr Palme.

"Within the last few years we've been able to really automate this process, speed up this process and really make it part of our routine care delivery for these patients," said Dr Palme.

Ms Flannery is now back in the classroom doing what she loves doing best, teaching.

She doesn't look like she has had her jaw removed and is ecstatic with the result.

"I get blown away when I think about it," she said.

"Tara's a rock star. You would hardly know she's had such incredibly destructive surgery," said Dr Palme.