No criminal charges will flow from misleading information given to South Australian health officials which sparked last month's short-lived statewide lockdown as a cluster of coronavirus case emerged in Adelaide.
Police conducted an investigation into a man who initially told contact tracers he had only picked up a takeaway meal from a venue, known to be a coronavirus hotspot, but later conceded he had worked at the business.
His initial information prompted SA to be placed into a six-day lockdown amid fears of growing community transmission, with officials later cutting that short to just three days after the fresh details were revealed.
Assistant Commissioner Peter Harvey said evidence collected during the investigation had been provided to the Director of Public Prosecutions and senior police prosecutors.
"In very simple terms, the advice provided back to investigators is that based on the limited evidence available for presentation to a court, the matter will likely not succeed or progress," Mr Harvey told reporters on Wednesday.
"Based on that advice, no criminal charge will be laid by the task force investigators against the male at the centre of the investigation.
"From a criminal investigation perspective, this matter is complete."
As the Parafield cluster emerged, Premier Steven Marshall was highly critical of the man's actions.
While in a statement issued through his lawyer, the man said he did not foresee or intend what unfolded.
"He is extremely remorseful and deeply sorry for any part his conduct played in any unnecessary lockdown actions," the statement said.
"My client's current focus is on cooperating with the authorities and completing quarantine.
"He is sincerely concerned about the impact of the lockdown on South Australians."
The statement said the man had limited access to government information and public comments on social media, but believed some information was not fair or accurate.
The end of the police investigation came as SA recorded a fourth consecutive day on Wednesday with no new COVID-19 infections.
That left the Parafield cluster at 33 cases with only 10 of those still considered active.
About 1000 close contacts remain in quarantine but that number has dropped significantly from a high of almost 6000.
Chief Public Health Officer Nicola Spurrier said every day without a new infection was good news, but cautioned that coronavirus had a 14-day incubation period.
She said it was still possible some people who had come in contact with the virus were yet to be located.
"Until we've gone the two full incubation cycles, the pressure is still on but also the requirement for people to get tested," Professor Spurrier said.
"That really is the only way that we will know we've overcome this.
"So we're not quite out of the woods yet, but certainly every day where we have zero numbers we can feel really happy."
Wednesday also marked the first day back at work for emergency department doctor Dharminy Thurairatnam, who diagnosed the first case in the cluster when an 81-year-old woman presented at the Lyell McEwin Hospital on November 13.
Dr Thurairatnam decided to swab the woman for COVID-19 when she noticed a mild cough.
"She didn't have specific symptoms at all, but I did notice the cough," she said.
"But that's not what she came in for. She was just feeling off and unwell.
"I didn't expect her to come back COVID positive. That was the last thing on my mind. We didn't have community transmission."
Australian Associated Press