LATEST: Big breakthrough in Melbourne’s mystery ‘Delta’ cluster

A genomic link has been made between a person who was in hotel quarantine in Melbourne and the West Melbourne ‘Delta’ COVID-19 cluster.

The health department confirmed the news on Tuesday.

It remains a mystery how the virus was transmitted, with no known link between the returned traveller and positive cases.

The Delta case landed in Melbourne from Sri Lanka on May 8 and tested positive to COVID-19 that day.

They were released on May 23.

Deputy Chief Health Officer Allen Cheng said there were currently four main working theories.

1. The case transmitted to, or was infected by, another passenger or staff on the flight and that person has gone into the community (there were 24 people in total on the plane).
2. The case transmitted the coronavirus after serving 14 days in hotel quarantine.
3. The case unknowingly transmitted to a staff member on the plane, airport or hotels.
4. The case transmitted to another resident in hotel quarantine, who then took the virus into the community.

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