A three-year-old girl is the latest person to be diagnosed with COVID-19 in the Northern Territory community.
It brings the current outbreak to 61 cases.
"She went to Katherine Hospital yesterday for some treatment and it was at that point she received a PCR test and that has come back positive," Health Minister Natasha Fyles said on Monday.
Health workers are interviewing the toddler's seven household contacts in a bid to contact trace their movements.
More cases are expected.
Ms Fyles said the girl's infection is likely to be linked to persistent positive wastewater tests in the town, which is 320km south of Darwin.
A lockout in Katherine has been extended for 24 hours and is now scheduled to end at midday on Wednesday.
A lockdown in the nearby Binjari Aboriginal community will ease to a lockout.
Meanwhile, a returned traveller from London has also tested positive for the virus, along with a close contact of a traveller from Melbourne.
Both are in quarantine and not considered a threat to the NT community.
Across the NT, 95 per cent of eligible people have had one vaccine dose and 89 per cent are fully vaccinated, according to NT Health.
