In northern NSW, a COVID-19 denier has put 150,000 people into lockdown.

Authorities and contact tracers have their work cut out for them in Byron Bay today, as the COVID positive man who triggered the northern NSW seven-day lockdown allegedly does not 'believe' in the virus.

Areas in northern NSW woke up to their first full day of lockdown on Tuesday morning, with stay-at-home orders imposed upon Byron Shire, Richmond Valley, Lismore, and Ballina Shire at 6pm on Monday evening.

Those in the area are confined to their homes unless leaving for essential shopping, for medical appointments or to get vaccinated, or to fulfil caring duties.

Watch: How to talk to anti-vaxxers. Post continues below video.

The lockdown was triggered after a 50-year-old man from Sydney travelled there on July 31 and subsequently tested positive for COVID-19.

The man, who was travelling with two teenagers who have also subsequently tested positive, is currently being treated at Lismore Base Hospital.

Authorities are still to determine the source of his infection but suspect he contracted the virus from his wife.

He had reportedly travelled north to view real estate, which is allowed under current restrictions, but concrete answers to so many questions currently remain unanswered because the man is allegedly a COVID-denier.

"I've heard he didn't believe in the virus. From what I understand, he is not cooperating," Byron Shire mayor Michael Lyon told ABC radio on Tuesday.

Lyon said locals feared an outbreak as there was no record of the venues the man had been to, and he had not been wearing a mask or social distancing.

Image: Getty.

He has also been uncooperative with authorities and contact tracers since testing positive.

"What we do know is he hadn't been checking in anywhere, hasn't used QR codes, hasn't been self-isolating when he got sick, he didn't get tested until he was really sick," he said.

"It's been very difficult for police and health authorities to track down where he's been, it's ridiculous, you have to wonder what people are thinking when it comes to a situation like this."

Lyon said the behaviour was unacceptable.

"When it happens because someone is complacent or negligent it's unacceptable, it's worse than stupidity, when you just don't give a sh*t, that's next level for me," he said.

The message for Sunday (and every day really) thanks to Byron Shire Council. #COVID19Aus pic.twitter.com/3p39b8rATk

— Jen King 🌻 (@JustJenKing) August 7, 2021

At Tuesday's press conference, Dr Kerry Chant said there had been no additional cases linked to the man and his children to 8pm on Monday evening.

Premier Gladys Berejiklian said "people know what is right and wrong" and "we expect people to do the right thing".

NSW Minister for Health and Medical Research Brad Hazzard would not comment on the man's conduct so as not to "prejudice" police enquires, which are ongoing, though he did address it broadly.

"What worries me is no matter what legal orders or requirements are in place, you can't legislate against stupidity, arrogance and entitlement," he said.

"If people applied the rules, if they complied with the rules and law and applied an element of common sense and modicum of decency to the rest of the community, we would be fine."

Queensland authorities will now beef up patrols on its southern border, though the man did not cross into the state.

"He travelled from Sydney to Byron Bay on 31 July and never travelled into Queensland. That is good. It is reassuring but having said that, anyone who has been in those four LGAs while he was there needs to now stay-at-home except those essential reasons," Chief Health Officer Dr Jeanette Young said.

Feature image: Getty.

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