Anyone breaking Queensland's tough rules to limit the spread of COVID-19 risks being jailed for up to six months.
The state government will this week amend legislation to hike up the penalty for individuals caught breaking the public health directions issued by Chief Health Officer Dr Jeannette Young.
The current penalty is a fine ranging from $1300 to $4003.
"In some cases, that fine appears to not be a sufficient penalty," Deputy Premier Steven Miles said on Tuesday.
"Perhaps people from other states think they might get away without having to pay for it, perhaps people think that $4000 is worth it.
"The maximum penalty, on the spot, will be $4003 or up to six months' imprisonment, and I hope that will demonstrate to the public just how serious we are about enforcing these measures."
Meanwhile, 18 people in Queensland who went to the Crossroads Hotel in southwest Sydney have been tested for COVID-19.
Results for 11 of them were negative, and the others are still pending.
"They came forward and they said they had been to the hotel and they got tested," Dr Young said.
Nearly 30 COVID-19 cases have already been linked to that outbreak, and Dr Young expects the number to climb.
Consequently Queensland added the NSW cities of Campbelltown and Liverpool to the list of coronavirus hotspots.
Police at Queensland's borders are now stopping every vehicle with NSW number plates and Queenslanders who have been to the hotspots in the last 14 days must quarantine in a hotel.
Anyone else who has been there will be turned away.
"No one travelling from those cities will be able to quarantine in Queensland and will be turned away at the border," Premier Annastacia Palaszczuk told parliament.
"Those who test our seriousness about our borders will learn a harsh lesson."
Meanwhile, singer and television personality Dannii Minogue has avoided 14 days in hotel quarantine at her own expense after being given an exemption to stay at a home.
Defence force personnel, maritime workers, consular officials, flight crews, entertainers and sportspeople are among those who are exempt from hotel quarantine.
Minogue is one of 38 people granted an exemption.
"They need to then quarantine in another place that I'm satisfied adheres to the same requirements," Dr Young added.
"There's no special treatment for anyone."
Dr Young said Minogue was under strict, if not stricter quarantine, at a private residence that has been organised by a third party who will be responsible for her adherence to the rules.
Officials have processed 14,345 people through Queensland's airports since noon on Friday, and stopped 22,459 vehicles on the state's highways.
Australian Associated Press