But ACT Chief Minister Andrew Barr hit back, saying he was not interested in having "whose poo it was arguments" with the Deputy Premier.

Health authorities have urged people in Merimbula to come forward for testing after the Covid fragments were detected. No cases have yet been reported in the far south coast region.

Mr Barilaro told reporters in Sydney that authorities had been closely monitoring the region due to its proximity to Canberra.

"We know that many people from Canberra have moved to the south coast," he said.

"It's an area that has been quite clean from Covid for a long time and we are asking the community to come out and be tested immediately, even for the mildest of symptoms."

But Mr Barr argued the fragments were just as likely to come from NSW, as there were Covid cases across the state and there was no way to tell where it came from.

"I don't think the sewage detection is quite that sophisticated to be able to tell whether it's a Canberran's poo or somebody else's," he said.

"Does John know something about the poo that other people don't?

"I mean, if he's got scientific evidence that can back it up, that it's Canberra poo. Okay. All right.

"But I mean, seriously, I'm just not interested in having whose poo it was arguments with John Barilaro at the moment."

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NSW reported a record 919 cases on Wednesday. There were nine new cases in ACT.

Mr Barilaro has previously been accused over comments he has made about an "escalating crisis" and a "threat coming out of Canberra".

The Deputy Premier has previously defended those comments, saying he did not mean to offend or blame Canberra but said the capital's outbreak did pose a risk.

"And I don't say that to offend them, because Canberra will say it all started in NSW," he told regional journalists last week.

"Every time I say, you know, the issue in Canberra impacts us, they seem to get offended.

"It's not blaming them. It's just the reality."

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