An independent report into South Australian public schools has uncovered instances of misconduct, including principals hiring family members for maintenance and cleaning work at inflated prices.
The Ernst and Young report was commissioned by the Education Department and was prepared in the lead-up to the introduction of the new independent commission against corruption.
It has also revealed cases of theft and fraudulent cash management strategies.
The State Opposition's education spokesman, David Pisoni, obtained the report under Freedom of Information laws.
He says the revelations are particularly damning in the wake of other allegations about the department's handling of cases of sexual abuse in schools.
"I don't know what it takes for this Government, for this Minister, to take some leadership and to deal with the culture that's in the department that is not revealing details to parents," he said.
Mr Pisoni says the report highlighted the need for a better system of reporting cases of potential corruption.
"There's another area here about the way whistleblowers are dealt with... They need to have their options broadened so they can in fact report corrupt or improper behaviour," he said.
The department's deputy chief executive, Gino Degennaro, says those responsible for the actions highlighted in the report have already been reprimanded.
"We take any risk of misconduct and those sorts of things quite seriously, very seriously and where these occur we take prompt action," he said.
"When matters arise they are acted on at the time, fully investigated and fully taken to task the persons who may have conducted themselves in inappropriate ways."
Mr Degennaro says the report vindicates department procedures for responding to misconduct.
"It showed that our internal control environment works but we could make improvement to it," he said.