Adelaide University’s vice-chancellor Peter Rathjen has been under investigation for alleged misconduct, and has now resigned due to ill health.

Independent Commissioner Against Corruption (ICAC) Bruce Lander has confirmed that “an investigation in respect of allegations of improper conduct” has been launched into Adelaide University vice-chancellor Peter Rathjen.

The statement stressed that the existence of an investigation “must not be construed as a finding that any person has engaged in impropriety”.

“That will be a matter for findings at the conclusion of the investigation,” the statement said.

“Secondly, my investigation is in respect of potential issues of serious or systemic misconduct and maladministration, not corruption,” Mr Lander added.

“Given the legislation under which I operate is geared toward investigations of these kind being conducted in private I am not in a position to offer further public comment until such time as my investigation has concluded.”

Days after the statement from the ICAC, chancellor Catherine Branson wrote to staff and students announcing Mr Rathjen’s resignation.

“I am writing to inform you that the university's council has accepted the resignation of vice-chancellor Professor Peter Rathjen AO, due to ill health,” her email reads.

“The university extends its appreciation for the contribution Professor Rathjen has made since taking up the role in 2018.

“The university will make an announcement about the search for a new vice-chancellor in due course.”