Anyone who attended BP Euroa at 29 Tarcombe St between 5 pm and 6 pm on Monday, May 24 must get tested immediately and quarantine for 14 days.
This comes after it was revealed a Victorian man visited the site while possibly infectious.
The man was travelling back to Melbourne on May 24 with his family following a holiday in Jervis Bay when he stopped at the BP.
Chris Richardson, who is the general manager of Vantage Fuels which operates BP Euroa, said the site was currently closed for deep-cleaning.
Following health department advice, two BP staff members are isolating for 14 days, while other workers can return to work once they receive a negative result.
"All employees who worked at the site have been notified of the of the situation, are being tested, and are isolating and closely monitoring for any symptoms," he said.
"No staff have exhibited any symptoms to date.
"Vantage fuels is closely following the advice and requirements of the Victorian Department of Health following this incident."
Mr Richardson said since COVID-19, all sites had followed increased sanitising procedures including regular cleaning of high-touch surfaces.
"The safety and wellbeing of our employees and customers is our highest priority and we want to minimise their exposure and risk to COVID-19," he said.
The Victorian man visited several other sites on his trip home, including the BP truck stop at Glenrowan.
Anyone who visited the truck stop on Monday, May 24 between 4 pm and 4.30pm is ordered to isolate, get tested and stay isolated until they receive a negative result.
The Victorian Health Department said it was working closely with NSW Health to test, trace and isolate the contacts of the newly-identified positive case.
The man reported the onset of symptoms on May 25, the day after he returned to Melbourne, and was tested on May 31.
His spouse and two children have also tested positive for COVID-19 and were included in Wednesday's numbers.
Health authorities are still investigating which family member caught the infection first, and where they acquired it.
A pop-up COVID-19 testing clinic was established at Euroa Health on Wednesday in response to the emerging situation.
Strathbogie Shire Council Mayor Chris Raeburn encouraged the community to remain vigilant and get tested if they experienced any COVID-19 symptoms.
"As a community, we can get through this by working together and continuing to do the right thing," Cr Raeburn said.
"The Strathbogie Shire community has already shown how it can follow restrictions and stay safe, we need to stick together to make sure this continues.
"We also remind our community to remember to check in on family and friends during this challenging time."
Today's cases bring the growing Melbourne outbreak to a total of 60 infections.
For a full list of Victoria's more than 350 exposure sites, visit coronavirus.vic.gov.au/exposure-sites
NSW Health has also listed a number of exposure sites in Jervis Bay and Goulburn, which can be viewed at health.nsw.gov.au
COVID-19 testing is available at the GV Health Acute Respiratory Clinic, Graham St, Shepparton.
Opening hours are 8 am to 4 pm, seven days a week.