The man in his 20s flew from Kabul to Sydney, then onto the Sunshine Coast, using diplomatic paperwork to avoid mandatory two-week isolation on arrival in Australia.

Premier Annastacia Palaszczuk says the man landed in Queensland on Friday with an exemption provided by the NSW authorities and a Department of Foreign Affairs and Trade letter.

He was diagnosed with COVID-19 on Sunday and is now in self-isolation with his wife in Toowoomba.

However, it has since been revealed the man is not a consular staff member, but a private security contractor.

Queensland police have been asked to investigate the source of the man's documentation.

"If there is any suggestion that it is not an authentic letter, then that needs to be investigated by police," Ms Palaszczuk told reporters on Tuesday.

"We are now in a situation where we need these loopholes closed.

"It is not too much to be asking people who are returning from overseas to do the mandatory quarantining."

The premier initially said she would raise the issue at national cabinet on Friday, but on Tuesday evening said she could not wait for a nationally consistent approach.

The ban will come in to effect from Wednesday.

It comes as health authorities continue their attempts to trace 14 people who were on the Jetstar flight with the man to Maroochydore on Friday.

Chief Health Officer Jeannette Young said two passengers from the flight had left no contact details, as it was not a requirement on domestic routes.

"The airline cannot tell me how I can get hold of those people," she said.

Meanwhile, another three people have been caught trying to dodge quarantine in Queensland after travelling from coronavirus-ravaged Victoria.

The men, aged 23, 25 and 29, failed to declare they had been to the hot spot when they crossed into the state at Coolangatta after allegedly spending several weeks in Melbourne.

Police placed the trio, from Logan south of Brisbane, into hotel quarantine, where they are awaiting their COVID-19 test results.

Deputy Commissioner Steve Gollschewski says the men were carrying passes stating they had not been to a hotspot.

"One of those persons has been tested, yesterday, which exposed they had been in the Victorian area," he told reporters on Tuesday.

All three have been issued with court notices and investigations are ongoing.

"It's really, really disappointing ... that people in our community are still telling lies and deliberately trying to mislead the system to get back into our state," Mr Gollschewski said.

Australian Associated Press