NSW Health has identified a list of exposure sites, including locations in Goulburn, Jervis Bay, Hyams Beach and Vincentia.

The person with COVID-19 visited the following locations:

NSW Health has advised that list may grow and has asked people to monitor its website.

Anyone in the ACT who had attended exposure sites at Goulburn, Hyams Beach, Vincentia and Jervis Bay, at the specific times and dates, must quarantine for 14 days from the time they attended, regardless of a negative test result.

They must also complete an online declaration form, which will be available on the ACT COVID-19 website on Wednesday evening, and get tested.

Non-ACT residents who visited an exposure site cannot enter the territory without exemption.

In a statement, ACT Health advised Canberrans not currently in the territory to follow the advice of the state they were in.

ACT residents who attended one of the exposure sites and is still in NSW will be required to seek an exemption from the state government to leave quarantine.

ACT Health said those residents returning to Canberra who attended an exposure site should also apply for an exemption to return home.

"So that we can assist you with your safe return to the ACT. Quarantine requirements will apply," ACT Health said in a statement.

NSW Health has asked anyone who has visited Jervis Bay since May 22 to be especially vigilant for the onset of even the mildest of cold-like symptoms.

If symptoms appear, people are urged to come forward immediately and isolate until a negative result is received.

Victorian health authorities have warned of potential "stranger-to-stranger transmission" of this strain of the virus.

At least four instances of transmission had been detected in Victoria between people who were unknown to each other.

With previous variants, transmission had traditionally occurred in the home, in the workplace or where people known to each other come into close contact.

In its public health alert issued on Tuesday evening, NSW Health asked Jervis Bay residents to be especially vigilant for symptoms of COVID-19.

People who visited Green Patch campground, Booderee National Park and Village Bay Road in Jervis Bay at any time on Sunday, May 23 to 9am on Monday, May 24 are classified as a close contact and must immediately get tested and self-isolate.

In Goulburn, owners of the popular stop for travellers, Trapper's Bakery, had made the decision to close from Wednesday until they received further direction.

Shell Coles Express Big Merino remained open.

Goulburn Mulwaree general manager Warwick Bennett said council would meet on Wednesday to discuss a directive for businesses.

Victoria's "circuit breaker" lockdown has been extended a further seven days after six locally acquired cases of coronavirus were reported.

The Melbourne resident returning from NSW also visited locations in Victoria while infected, adding to the list of exposure sites there.

Six more sites were added, including three BP truck stops along the Hume Freeway at Glenrowan, Euroa and Wallan on May 24.

While metropolitan Melbourne will remain locked down for another week, it is likely restrictions will ease for regional Victoria from Thursday night.

"We'll use the next 24 hours to continue tracing and testing and confirm this change can go ahead," acting Premier James Merlino said.

ACT Health is yet to determine how the news would impact Canberrans isolating after returning from Victoria.

The Chief Health Officer is expected to make an announcement on Thursday.

Stay at home requirements were imposed on anyone entering the ACT from Victoria from the beginning of the state's lockdown on May 28.

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