Unions say they’re ‘deeply concerned’ about claims of the underpayment and bullying of staff at travel giant Flight Centre.

The Australian Services Union on Thursday it it had raised the issues previously with the Fair Work Ombudsman but more evidence had been brought to light in an investigation by the ABC.

‘We are currently in discussions with Flight Centre, where we aim to significantly improve workers’ pay and conditions and bring about significant change,’ the ASU said in a statement.