Queensland Deputy Premier Steven Miles said state knew of "at least one" rule breaker ahead of border ban

Queensland Premier Annastacia Palaszczuk announced on Wednesday the state borders would close to NSW and the ACT from 1am Saturday, with both jurisdictions declared hotspots.

Queensland Deputy Premier Steven Miles told ABC Radio National it was an extreme move to close off the sunshine state to the ACT over one man who had been charged over the alleged "flagrant" rule breach.

Police allege he travelled from a Sydney coronavirus hotspot to Canberra to board a flight into Queensland.

"It was a pretty flagrant [breach], they said they were doing it to get around the restrictions," he told ABC Radio National.

"We're seeing a growing number of people trying to find ways to sneak in to the state and we needed to give our police the tools they needed to keep people out who have been in those hotspots."

Mr Miles said police had charged more than a dozen people who tried to sneak into Queensland, most via NSW.

"NSW is going a very good job of managing their cases but Victoria continues to escalate," he said.

"We've seen in Victoria and NSW how one case can lead to dozens if not hundreds."

Queensland borders were already closed to Victoria and parts of NSW deemed hotspots including greater Sydney.

The ACT has gone almost a month without reporting a new cases of coronavirus and nearly a week without an active case.

Chief Minister Andrew Barr said there was no forewarning of the decision but it was "a fact of life" that most jurisdictions were treating the ACT and NSW the same, despite Canberra's low case numbers.

Read more: 'We can't go anywhere': Border closure delays Canberra family reunion

He said he wasn't aware of people using Canberra to flout lockdown rules but was open to addressing the issue.

Queenslanders returning from the ACT or NSW will have to pay for 14-days mandatory hotel quarantine.

Visitors will be denied entry except for "rare" exemptions.

"There have been a large number of active cases in Victoria, and we are continuing to see cases in NSW. This is a very concerning situation," Ms Palaszczuk said.

"We cannot risk a second wave. We have to act decisively and today we have acted quickly. We have put Queenslanders first."