Update: A food delivery worker breached hotel quarantine at the Pacific Suites Hotel after bypassing security and using an alternative entrance to go straight to a traveller's room.
Canberra police are investigating a possible breach of hotel quarantine after a person reportedly entered the Pacific Suites Hotel and bypassed security.
About 120 recently returned travellers are completing their mandatory 14-day quarantine at the Braddon hotel.
ACT Policing received information about a possible unauthorised person attending the hotel.
An ACT Health spokesman confirmed authorities were investigating the reported breach.
"We are conducting enquiries to ascertain the circumstances surrounding the report," an ACT Health spokesman said.
"While this is being investigated, ACT Health is confident there is no public health risk to the ACT community."
All returned travellers currently quarantining at the Pacific Suites were tested for COVID-19 Wednesday, with all returning negative results.
About 120 passengers on a Singapore Airlines repatriation flight arrived in Canberra on November 25.
They were transported to their hotel quarantine on Northbourne Avenue by Australian Federal Police officers.
ACT Policing and Australian Defence Force staff are responsible for overseeing the returning travellers at the Pacific Suites Canberra Hotel.
The possible breach comes after the ACT this week announced it would not be taking any further repatriation flights for the rest of the year.
Chief Minister Andrew Barr had previously said the territory would take an additional flight before Christmas.
An ACT Health spokeswoman earlier this week said the territory was working towards accepting more flights next year.
"This will allow enough time for the Commonwealth government to co-ordinate a flight and for ACT Health to prepare quarantine arrangements," she said.
"This work includes securing appropriate accommodation, ensuring capacity and resourcing and organising staffing in collaboration with ACT police."