Anyone who visited the supermarket or pharmacy from 9am to 11.30am on Monday is considered a casual contact and must get tested and self isolate.

An investigation into the source of the two cases began this week after two people understood to live in Queanbeyan and work in the ACT contracted the virus.

The discovery was followed by an announcement regional NSW would remain in lockdown until at least August 28 to align with the current end date of the Sydney lockdown.

NSW Deputy Premier John Barilaro told media this week the "escalating crisis occurring in Canberra" was causing concern for the surrounding regions.

He said he was not trying to offend or blame anyone from the ACT it was just the reality.

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The first case detected in the ACT outbreak has confirmed links to greater Sydney.

NSW set a grim new record on Thursday with 681 new locally acquired Covid cases, including an outbreak in the state's west which has now grown to 167 cases.

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