A national study from accounting firm Price Waterhouse Coopers [[PWC]] found 13 per cent of Australia's workforce is affected by underpayment, costing workers an estimated $1.35 billion a year.
But there are particular groups hit hardest by the system, and it's those who are already struggling to find stable employment.
A report by Unions New South Wales reveals over a third of workers were paid or offered a lower salary because of their visa type and more than a quarter were paid or offered a lower wage because of their nationality.
The Unions' Secretary Mark Morey says employers are targeting workers from culturally and linguistically diverse backgrounds.
The important thing about Australia is it is a country that has given migrants for 200 years an opportunity for a better life. The current system that was established by the former coalition government is a system that is set up to facilitate ongoing exploitation of visa holders to silence those who are being exploited, and to ensure that the model becomes a business model and a catch us if you can model of operation, this needs to cease.