The highly contagious UK variant of COVID-19 has been detected in a quarantining traveller in the Northern Territory.
The NT government said on Saturday that a 26-year-old woman arrived on a repatriation flight from London on December 30 and tested positive the following day.
The case was reported in the territory's daily numbers on January 2, but genomic testing results confirming the more infectious strain were not received until Friday.
"This is the first time this strain has been detected in Northern Territory quarantine facilities," the government statement said.
The woman remains in isolation at the Howard Springs quarantine facility and there are no other positive cases from the same flight.
Passengers and air crew from the flight have been tested twice and will be re-tested again on Saturday as an extra precaution, the government said. All remain in quarantine.
The UK variant of the virus has been detected in hotel quarantine in several other Australian states and in a locally acquired Brisbane case, prompting a three-day lockdown of the Greater Brisbane region.