SafeWork SA has re-classified the death of regional nurse Gayle Woodford as work-related, following a review.
SafeWork SA Executive Director Martyn Campbell, who commenced work with the agency in August 2017, reviewed the original investigation into the matter following concerns raised by Mrs Woodford's family on the program Australian Story last month.
Mr Campbell said SafeWork SA should not have told Mrs Woodford's family that her death was not work-related.
"Based on the evidence available at the time, the finding that this death was not a workplace fatality was incorrect," he said.
Mr Campbell met with Mrs Woodford's family late last week to apologise for SafeWork's handling of this matter.
"I also regret any frustration this may have generated in the broader community," he said.
Mr Campbell said SafeWork SA has received new information relating to Mrs Woodford's death that has led to the agency reopening its investigation into the matter.
He also said SafeWork SA is undertaking a range of measures to ensure this error is not repeated.
"We have begun a comprehensive retraining program for our current staff and are recruiting to increase our investigative capability," he said.
"I am also looking at how SafeWork SA can identify whether there are other cases that need to be reassessed in light of this matter."
As the matter is now subject to investigation, further comment cannot be made at this point.