Victorian health authorities have confirmed a hotel quarantine worker has tested positive for the highly contagious British strain of the coronavirus.

Chief health officer Brett Sutton said that had been expected – four of the six people with COVID in the Grand Hyatt, where the 26-year-old man worked in Australian Open quarantine, had the British variant.

“We’re confident at the moment it’s not been picked up in the community but from one of the residents in the hotel,” Professor Sutton said.

He said authorities were also fairly confident there had been no breach of virus protocols in the hotel. They still considered airborne transmission most likely for the man’s infection.

“Droplet spread is managed when you’re more than a metre-and-a-half away and you’re wearing PPE,” he said.

“But … aerosolised particulars can move even further than that. We need to be as precautionary as we possibly can. We can re-examine that.”

• See all the latest Victorian virus exposure sites here

The news comes as Victoria recorded no new locally acquired coronavirus cases.

Friday’s confirmation of zero community cases came from 14,612 tests in the previous 24 hours as Melburnians turned out in their droves at testing centres across the city.

“While there are still days that will be relevant to us – tomorrow is not over yet – these are, in some respects, the very best outcomes we could have hoped for,” Premier Daniel Andrews said.

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In further good news for Victorians, 17 of the infected hotel worker’s closest contacts have all been tested for the virus. So far, 16 of those tests have come back and all are negative.

“Those he has spent the most time with during his most infectious period have all, to this point, come back negative. It doesn’t mean that they might not test positive at a later point and that’s why them completing the isolation and doing as we’ve asked them to do is so important,” Mr Andrews said.

“But these are good signs, very good signs, that we caught this in good time.”

Earlier, Victorian hotel quarantine organisers confirmed they held a party to thank those involved in the Australian Open program just days before the worker tested positive to COVID.

COVID-19 Quarantine Victoria has confirmed it held a “small function” for 60 staff at the View Hotel – one of three hotels used to quarantine Australian Open tennis players, officials and support staff – last Sunday.

Three days later the 26-year-old man returned his positive test, ending Victoria’s 28-day run without community transmission.

“CQV held a small function to thank operational staff including team leaders, site and general managers for their considerable efforts in facilitating the complex quarantine program for the Australian Open,” a government spokeswoman said in a statement.

“Staff and guests observed the same public health safety requirements that all Victorians are required to adhere to when attending public gatherings.”

• Pressure on PM over quarantine as leaks mount

The quarantine leak has also been a hitch for Australian Open arrangements. Warm-up matches were cancelled on Thursday, after the positive case emerged, but were to resume on Friday.

More than 500 tennis players, officials and support staff were in isolation on Thursday, awaiting virus test results.

On Friday, Tennis Australia boss Craig Tiley said 495 of those had returned negative results, with just 12 still to come in.

“Hopefully in the next few hours we get the positive outcome that all are negative,” he told Melbourne radio station 3AW.

Mr Tiley said the Open would go ahead as planned from Monday. There has been no change to crowd arrangements, which are initially capped between 25,000 to 30,000 each day.

The virus scare has also prompted some states to introduce new testing requirements for people travelling from Victoria, including NSW, South Australia, Tasmania, Queensland and Western Australia.

-with AAP