Melbourne COVID outbreak linked to an arrival from Sri Lanka

The source of Melbourne's most worrying Covid cluster which has left millions locked down for two weeks has finally been found, a returned traveller from Sri Lanka who arrived in the city a month ago.

Five million people locked down in the city could finally be freed within days with just two new infections found on Tuesday, both linked to known sources.  

Acting Premier James Merlino said authorities had genomically linked the West Melbourne Delta cluster to a man in his 40s who arrived from Sri Lanka on May 8.

The man, from the Glen Eira area, tested positive the same day and was moved from the Novotel Ibis to the Holiday Inn 'health hotel' on May 14 before being released on May 23.

His genomic sequence is a match to the second of the two families identified at the North Melbourne Primary School as part of the West Melbourne outbreak.

But authorities are still unsure how the virus was transmitted from the returned traveller to the infected family.

Victoria's Deputy Chief Health Officer Allen Cheng said there were four main theories, with some more likely than others.

'At this stage, we have not identified any high-risk incidents or interactions with staff or residents that may provide a clue as to the link to this outbreak,' Professor Cheng told reporters on Tuesday.

Mr Merlino said Melbourne and regional Victoria are 'on track' to ease restrictions later this week.

'So I just want to send that very reassuring message to all Victorians. Nothing about today changes our plans,' he said on Tuesday.

Acting Police and Emergency Services Minister Danny Pearson said all 24 flight passengers and a Skybus crew had returned negative tests.

Some 268 COVID-19 Quarantine Victoria staff worked at the Novotel Ibis on May 8 and 9, and 360 staff at the Holiday Inn.

They along with 12 residents housed on the same floor of the Novotel Ibis have tested negative.

The West Melbourne outbreak is linked to the North Melbourne Primary School, and involves several children, while the other outbreaks in the city are linked to the Indian Cappa variant.

The welcome news means Melbourne's lockdown is likely to be lifted as scheduled at 11.59pm on Thursday, with restrictions likely easing to those currently in place in regional Victoria, source claimed.