Macquarie University says it alerted the NSW corruption watchdog to "inappropriate financial behaviour" that has triggered a public inquiry into a former IT manager who worked at three of the state's universities.

Brett Roberts, who worked in IT management at the University of Sydney, Macquarie University and the University of Newcastle between 2005 and 2013, is being investigated over allegations he issued "false invoices" to his employers to obtain corrupt benefits.

Macquarie University says it takes its "financial and fiduciary responsibilities very seriously". Credit:Fiona Morris

The Independent Commission Against Corruption announced on Wednesday it would hold a three-day public hearing into the inquiry, codenamed Operation Misto, from February 16.

Macquarie University said it reported "possible corrupt conduct" to the ICAC after an internal misconduct investigation found Mr Roberts had "failed to comply with the university's contract management policy and procedure".