Canberra, Jan 11 (IANS): The Australian Broadcasting Corp (ABC) on Friday admitted to underpaying 2,500 casual staff over the past six years.

ABC's head of public affairs Emma McDonald released a statement, acknowledging the issue and suggesting that miscalculated penalty rates, loadings and allowances are behind the discrepancies, reports Xinhua news agency.

"A detailed review is underway to confirm how penalties, allowances and loadings should have been calculated and applied over the past six years to about 2,500 'flat-rate' casual staff," McDonald said.

The ABC is now liaising with workers rights organisations, including the Community and Public Sector Union (CPSU), who were responsible for uncovering the discrepancies through an ongoing audit which began in August last year.

In a statement, the CPSU described the underpayment as "negligent" and the ABC's admission of the issue as "belated".

A test case conducted by CPSU showed that one employee from the ABC's news division was underpaid by $13,657.

"Clearly the total bill for underpaid wages is going to be substantial and comes at a time when the ABC can ill afford it," CPSU ABC section secretary Sinddy Ealy said.

The ABC has apologised to all underpaid employees and said they are actively working to remedy the situation.