The ACT government has admitted to underpaying superannuation to 633 current and former staff members of the Cultural Facilities Corporation (CFC) for the last 13 years.
The CFC is an ACT government enterprise, which mainly manages hospitality and ticketing staff at the Canberra Theatre Centre.
In an email sent to workers and seen by the ABC, underpaid staff were told it was a "historical error" that occurred in the set-up of the CFC's payroll software. The software was installed in 2009.
The email specified that 63 per cent of all staff who had worked for the CFC since then were impacted by the underpayments, which totalled over $315,000.
In a statement to the ABC, a spokeswoman for the CFC said "the problem was identified as a result of a routine internal audit".
'It took two years to let staff know and to let the union know'
Community and Public Sector Union ACT regional secretary, Maddy Northam said the CFC was made aware of the error in 2020.
The CFC said the issue had been "very large and complex" to rectify, including reviewing 69,391 individual payslips, which it said had "taken considerable time and effort".
But Ms Northam said staff members were "deeply concerned" and it was "pretty scathing on the organisation that they failed to pick up on it".
"Of course, it's disappointing that this is a government entity," she said.
The issue is in the process of being resolved, with the full amount plus interest set to be paid back to each affected worker.