Immigrant advocates want the government to prioritise the toughening up of penalties for employers exploiting immigrant workers.
Those working with immigrant employees say they fear the exploitation of immigrant labour is becoming entrenched in New Zealand society.
They point to the many examples of immigrants working extremely long hours for pay that can be as little as a third of the minimum wage and of staff being asked to lend tens of thousands of dollars to the business they work for, often with very little chance of it being repaid.
An employment advocate in Auckland, May Moncur, says many of the workers are threatened with deportation if they complain in any way.
She says under the current legislation, it is too easy for employers to get away with treating workers poorly and she believes New Zealand is getting a bad reputation.
The Council of Trade Unions says employers who exploit migrants should be banned from bringing in overseas workers until they show they have improved their practices.
Labour Minister Simon Bridges says he is looking into whether there need to be further criminal penalties for individuals who exploit their staff.
More about immigrant exploitation and the protection of vulnerable workers be heard on Insight on Sunday.