Is this the REAL reason for Melbourne's outbreak? More than 5,000 returning travellers have REFUSED coronavirus tests - but authorities let them go home anyway

• Victoria recorded another 30 positive cases of deadly coronavirus on Friday
• Data shows 5,000 returning travellers refused to be tested for coronavirus 
• Vic will look into forcing travellers to stay in quarantine until they test negative  
• About 4,800 infrared thermometers are being shipped to vacation spots in Vic

More than 5,000 returning travellers refused to be tested for coronavirus in Victoria before being allowed to return to their homes, it has been revealed. 

On Friday, Victoria's deputy chief health officer Annaliese van Diemen acknowledged that about 30 per cent of returned travellers have refused a COVID-19 test.

Those people, around 5,000 in total, were then allowed back into the community even though they may have been infectious. 

Australia's Chief Medical Officer Brendan Murphy said states do have the power to force people to stay in quarantine until they return a negative test. 

Victoria said they will look into further enforcement measures while NSW said they will detain people for an extra 10 days if they refuse to be tested.    

About 4,800 infrared thermometers are being shipped to vacation spots while more testing clinics are being set up as the state struggles through a second spike in coronavirus infections. 

Dr van Diemen acknowledged that some people are automatically allowed into the community and said she was 'happy with the current regime'. 

'At the moment there is no requirement that they must undertake testing,' she said. 

'Everybody's offered testing on multiple occasions throughout their stay and we have, you know, very good uptake of that.

'At this point in time we're pretty happy with the current regimen. It's more stringent than most other places.' 

In the wake of the revelations, Professor Murphy said all travellers arriving in Australia will be tested before they are quarantined and again once they are allowed to leave.  

'That 30 per cent is quite a high rate, other states haven't seen the same rate of refusal,' he told reporters in Canberra on Friday.

'But states have the powers ... to say to someone, 'well, we won't let you out of quarantine until you've been tested and had a clear test'.

'We will ... make sure that people understand before they come that this is a requirement. I think most people will cooperate with that arrangement.' 

Victoria recorded 30 new cases on Friday with five of those in hotel quarantine, five detected through routine testing and another seven linked to known outbreaks. 

Another 13 cases are still under investigation.  

Premier Daniel Andrews announced plans to carry out a 'testing blitz' in 10 COVID-19 hotspot suburbs across Melbourne to bring the deadly virus under control. 

Officials say 20,000 tests have been done since Thursday, bringing the total tests undertaken in Victoria to date above 736,000.

Testing clinics will be set up on the Great Ocean Road and in the Victorian Alps to coincide with the holidays.

The health advice for Victorians is that they can travel within the state during the fortnight of the school holidays - as long as they are healthy.

 Anyone with virus symptoms, however mild, must stay home and undergo testing.

A health worker at the Orygen Youth Mental Health Facility has the virus, Dr van Diemen said on Friday.

'That facility is now in lockdown and we are working very closely with Melbourne health who run the facility,' she said.

'All of the deep cleaning requirements have been done there and testing will be undertaken as required.'

A McDonald's worker has also been confirmed as having COVID-19 and is linked to an outbreak in Wollert, which stemmed from 'various household parties and gatherings'.

'The St Monica's outbreak has been renamed as the Wollert outbreak because it has been apparent the major driver of this outbreak has been social occasions with some spillover into the school, so the worker at McDonald's is linked to that outbreak,' she said.

Meanwhile, dozens of Centrelink contract staff who live in Victoria's coronavirus hot spots have been stood down amid concerns at the risk of community transmission.

Hank Jongen, the general manager of Centrelink's parent agency Services Australia, said fewer than 100 staff who live in the affected COVID-19 hot spots work outside those areas.

'These staff have been advised to stay at home while we review and adapt to the latest health advice and prevent unnecessary movement in and out of those areas,' Mr Jongen said in a statement on Friday. 

There are 183 active cases in Victoria with six people currently in hospital. More than 1,700 people have recovered from the virus in the state. 

Dr van Diemen added health officials were working to contain two cases confirmed at a Coles distribution centre in Laverton in south-west Melbourne. 

'One of those cases is very clearly linked to a large outbreak at Keilor Downs, so we do have a very clear source of acquisition for that,' she said.

The Keilor Downs family outbreak in north-west Melbourne has now swelled to 19 infections, while a North Melbourne cluster has reached 15 cases.