Police are investigating allegations of inappropriate behaviour by an out of school hours (OSCH) worker in Adelaide, who was stood down from his role in early September.

It is believed five children are involved.

Education Minister Jennifer Rankine's office has confirmed a report about the case was first made to the Child Abuse Report Line on August 30.

The man was stood down from his out of school hours care role and a position as an school support officer by the Education Department on September 2.

On September 13 the school's governing council terminated his employment as an OSHC worker.

Governing councils have responsibility for out of school hours care programs.

On October 22 the man resigned from the SSO position.

The Opposition says it believes concerns about the case were first raised in April. No arrest has been made or charges laid.

Ms Rankine said a police investigation was ongoing and it was for that reason parents had not been notified of the case.

"We have to be very cautious about releasing information whilst investigations are ongoing," she said.

Opposition education spokesman David Pisoni said he knew of one parent at the school who was told of the concerns over the man's alleged actions by another parent.

"How can it be, given the enormous public interest in child protection in schools that at least one parent had to be informed by another parent, not the department, of the allegations leading to a staff member being stood down," he said.

Meanwhile, the man responsible for the State Government's internet, email, and telephone networks has quit to take up the same role in Queensland.

Chief Information Officer Andrew Mills will leave the South Australian public service on January 5 next year, after almost six years in the role.

Last week, Mr Mills was asked by Premier Jay Weatherill to facilitate a search by Telstra technicians for a missing email at the centre of the sex abuse case which sparked the Debelle royal commission.

The email, about the sexual assault of a student, was sent to Mr Weatherill's chief of staff, Simon Blewett, and forwarded to an unknown recipient.

Initial searches by police failed to find the recipient.

A parliamentary committee inquiring into issues stemming from the royal commission into school sex abuse cases wrote to Mr Weatherill asking him to allow further searches by Telstra.