A record 20,856 tests have been conducted over a 24-hour period and only one has returned a positive result. That was in someone already quarantined as a precaution due to having contact with a known case from the detention centre cluster.

Chief Health Officer Jeannette Young said contact tracing would determine whether the latest person to be infected had visited any public locations and put others at risk. If so, Queensland Health would add those locations to the scores already subject to alerts.

Young said five detention centre staff had passed the virus to six others, all of whom were in close contact, not strangers who have been infected in the community. No detainees or former detainees have tested positive.

“We have not seen any community transmission due to any of the original five cases of this,” Young said.

“There is still a risk over the next week that we will see that.”

While Young expects more cases, she does not believe there will be many and has been heartened by the level of testing. She said Queenslanders also appeared to be social distancing.

Queensland Health is still trying to determine the link between the cluster and the outbreak in Victoria, believed to be via the Logan cluster sparked by two young women bringing the infection back from Melbourne.

The Palaszczuk Government heralded a Federal Court judgment on Thursday as a legal endorsement for Queensland’s border restrictions.

Deputy Premier Steven Miles said the judgement, ostensibly in relation to restrictions in Western Australia, was a rebuke to critics including businessman Clive Palmer and Prime Minister Scott Morrison.

“Keeping borders closed is an effective and legal health measure,” Miles said.

However, policing the border remains a challenge: a motorist with a pass only allowing movement in the ‘border bubble’ region was found in Mackay, and the recently arrived superyacht Lady Pamela is now under criminal investigation suspected of lying about its route and the people onboard.

Premier Annastacia Palaszczuk said she was “disgusted” by the thought of people lying to enter Queensland and put others at risk.

Young said the people from the superyacht had been tested and placed into quarantine, and would be the focus of a “very serious investigation” by police.

Deputy Commissioner Steve Gollschewski said police took such matters seriously and would follow-through on any suggestion of wrong-doing.

“We’re going to be relentless,” Gollschewski said.

Young said exemptions had been granted to allow 10 superyachts to enter Queensland for maintenance and repairs.