UPDATE: A worker from the Granites Tanamai gold mine site who tested positive to COVID-19, and 70 of his work mates, are in quarantine in Howard Springs, with contact tracing started for the roughly 900 people known to have left the mine since June 18, the NT Government has said.

Chief Health Officer Hugh Heggie said there were no COVID-19 restrictions for the general public, but said people should social distance and use the Territory Check-In app.

“I want to be very clear. We are at risk,” Dr Heggie said.

The Granites mine is owned by Newmont and is about 540km northwest of Alice Springs. All workers on site, about 750 of them, have been put into isolation, the government has said.

The mine is on Aboriginal freehold land that is owned by the Warlpiri people but it is 270 km away from its closest neighbour, the Aboriginal community of Yuendumu, and it is about 325km from Lajamanu.

Chief Minister Michael Gunner gave a press conference – that the NT Independent was excluded from – and said the man had travelled from Bendigo and tested positive to an as yet unknown strain of Covid-19, but which was most likely the highly infectious Delta strain. However, an NT Independent source within government said it is a confirmed case of the Delta strain.

Mr Gunner said about 70 of the mine workers were considered close contacts and had been flown to quarantine at Howard Springs.

He said the man went into quarantine in Brisbane for a night on June 17, because of Queensland COVID restrictions for Victorians, and flew on a charter flight to the mine the following day because regional Victoria was not a COVID hotspot by NT authorities at that time.

The man received an alert on June 24 that the hotel he had stayed at in Brisbane was considered an exposure site and went into isolation, was tested and came back with a positive result at midnight last night, Mr Gunner said.

The media reported Mr Gunner said that there were about 900 FIFO workers who left the mine and traveled to places including Alice Springs and Darwin and Brisbane, during the time the man was at the mine.

“On the 24th of June, he received a text message from NSW Health advising in the hotel in Brisbane was a potential exposure site and he immediately isolated and got tested,” the media reported he said.

“He received the message from NSW as his driver’s license is currently from that state.

“As soon as his test came back positive, around midnight, approximately 12 hours ago, the Director of the Centre for Disease Control was notified, and our emergency procedures kicked in.

“Everyone on the mine site has gone into isolation, and the mine has started shut down processes and contact tracing has commenced.

“We are asking all 900 to identify where they are isolating [and] where they have travelled to another jurisdiction, we will advise that jurisdiction.

“So we are assuming it is the Delta variant, the worst-case scenario. It is better to over-prepare than underestimate the risk.”

The media report said Mr Gunner said the man was asymptomatic, but had been infectious from June 18 to June 24.

Editor’s note: An earlier version of this article said the NT would lockdown for three days. This was incorrect. The mine is in lockdown. The NT Independent apologises for the error.