Commonwealth Bank of Australia
The logo of the Commonwealth Bank of Australia (CBA) is displayed outside a branch in Sydney, Australia, March 21, 2016. Reuters/David Gray

The Commonwealth Bank (CBA) has agreed to reimburse the superannuation after the Finance Sector Union (FSU) brought up that the bank should repay the entitlement to part-time workers. The union said that a complaint would be filed to the Fair Work Commission if the bank would not take action.

"The CBA has been ripping off some of its lowest-paid staff since at least 2009. We are committed to make sure the bank pays up. It's bad enough that Australia's most profitable bank pays some of the lowest wages in the banking sector — now we are finding that part-time staff aren't getting their full superannuation entitlement," FSU national secretary Julia Angrisano.

The bank said in a statement that it would review the payments of part-time workers who worked in the past eight years. The bank would check the records from 2009 in detail, and it expected to complete the work by the end of June. It promised that any superannuation owed to an employee would be reimbursed.

However, the bank noted that in 2009, it decided that the superannuation was payable for ordinary hours worked by part-time employees. However, it did not apply to extra hours or overtime work. The bank said that its policy was based on the Superannuation Guarantee Ruling issued by the Australian Tax Office in 2009.

The bank was already looking at the issue in detail apart from the six cases that FSU raised. According to CBA, the six employees involved should have received extra superannuation entitlements of $180 per year on average from 2009. In total, FSU said that the cases could involve more than 7,000 workers but the bank has not yet released the current figures. On Tuesday, Commonwealth Bank chief executive Ian Narev would face the House Economics Committee in Canberra.

The bank has faced a scandal over its financial planning insurance arm, CommInsure. According to its former chief medical officer Ben Koh, the insurance company was allegedly denying and delaying claims and tampering of files in the chief medical officer opinion database. Koh added that some managers were leaning on doctors to change their opinions and cherry-picking the doctors.

However, CBA said in in its two-page document that the review on the case has been completed. The bank said that independent expert reviews were also conducted apart from the Deloitte review, DLA Piper and Ernst & Young. The bank's board concluded that there was nothing to support the concerns of wilful or widespread misconduct.