We were down to periods of several days between cases. There was talk of a trans-Tasman bubble. Several States and Territories were entirely free of infection.
https://en.wikipedia.org/wiki/COVID-19_pandemic_in_Australia#June_2020
The only new inputs were returning travellers. Quarantine them for two weeks, see if they have it. If not, set them free.
Victoria dropped the ball on this. Whose stupid idea was it to have a quarantine that allowed those being quarantined to have intimate congress with those outside?
The guards weren't even wearing masks!