Three new cases of locally transmitted COVID-19 have been detected in Sydney in the past 24 hours.

The latest is a couple from the Northern Beaches who visited a number of venues while infectious.

The woman in her 60s and man in his 70s are close contacts of each other but it’s not believed they are linked to other known cases.

The source of the cases is under investigation and the results of urgent genome sequencing is expected within 48-hours.

Mark McGowan says the state government will monitor the situation in New South Wales and re-instate travel restrictions if required.

A 45 year old man who drives international aircrew to and from Sydney airport has also tested positive.