A NSW man who prompted a COVID-19 scare in Adelaide when he absconded from a quarantine hotel gave false information to police, an investigation has found.

Police Commissioner Grant Stevens said the security breach was disappointing and should not have happened.

The 33-year-old had arrived in Adelaide from Singapore on a repatriation flight on August 3 and was required to spend 14 days in supervised isolation.

But on August 12 he left the hotel in a security breach and travelled to a nearby pub and a fast food outlet while spending several hours in the community.

The man was fully vaccinated and had returned negative COVID-19 tests on days one, five and nine of his quarantine.

On his return to the medi-hotel he submitted to another COVID-19 test, which was also negative.

The incident prompted a major investigation, which Mr Stevens said established the man left his room and entered a nearby fire exit in the space of seven seconds.

No one noticed

While recorded on CCTV, his movement in the corridor was not detected by personnel monitoring the area.

A short time later, he entered the hotel’s basement car park, where he was located by police near the exit.

Mr Stevens said the man provided false information which led the officers to believe he was a patron from a nearby business and had inadvertently found his way to the car park area.

The commissioner said the man’s movements should have been picked up by those monitoring the CCTV and the police patrol who came across him “should have asked more questions”.

Despite the breach, he said the robust processes in SA’s quarantine hotels remained at a very high standard.

“This isolated incident happened partly due to the close proximity of the man’s room to the fire exit and his lies to police,” Mr Stevens said.

The NSW man was charged with breaching the Emergency Management Act and pleaded guilty at an appearance in Adelaide Magistrates Court on Wednesday.

The court heard he had travelled to Scotland for father’s funeral and was overwhelmed with grief and stress after being separated from his family.

-AAP