Queenslanders who visited the regional New South Wales towns of Orange, Nyngan and Broken Hill between 2-3 January are being asked to get tested for COVID-19.
The alert comes after a positive COVID-19 case from NSW transited through the towns while infectious.
Queensland Chief Health Officer Dr Jeannette Young said she was treating this newest threat with "an abundance of caution".
"We know a person who was positive for COVID-19 has been out and about in these communities very recently," she said.
"There is every chance this individual has been in contact with holidaying or visiting Queenslanders who were also in these towns during this period.
"Everyone who has been in Orange, Nyngan and Broken Hill between 2-3 January should get tested tomorrow or earlier if possible, and quarantine at home until they receive a negative test result.
"If we do have any cases connected to this individual, it is absolutely critical we detect them before we see widespread community transmission.
"Additionally, I am concerned about the potential spread across regional NSW. Queenslanders who spent time in regional NSW over the holiday period should remain vigilant of their health and get tested if they show any COVID-19 symptoms."
Dr Young also reminded the general community to keep getting tested.
"Queenslanders have already performed incredibly well - we've have performed tens of thousands of tests in the past few days alone.
"But that doesn't mean we can be complacent - it takes just one undetected case to bring all our progress to an end."
To access a full list of COVID-19 testing locations, with interactive map and post code search, visit: https://www.qld.gov.au/health/conditions/health-alerts/coronavirus-covid-19/stay-informed/testing-and-fever-clinics
Remember, if your local testing clinic is crowded, consider attending another one.
