The Government says it will increase penalties against employers who exploit migrant workers.
Immigration Minister Michael Woodhouse says the current law is not addressing the problem and he has encouraged exploited migrants to speak up.
An investigation was launched last week into a claim that migrant workers at an Auckland restaurant were being paid just $4 an hour. The adult minimum wage in New Zealand is $13.75 an hour.
Mr Woodhouse says legislation to be introduced to Parliament in about a month would bring in a specific offence of exploiting migrants who hold temporary work visas, with proposed penalties of imprisonment for up to seven years and/or a fine of up to $100,000.
He is also proposing to deport employers who exploit workers if the offence is committed within 10 years of gaining residence.
Mr Woodhouse says unlawful migrants are already protected, and lawful migrants should have the same safeguards.
"I've instructed immigration officials to put the emphasis onto the employers rather than the employees.
"So if an employee is working in breach of the visa conditions and is required to reapply for a visa, the fact that they may have been in breach will not be taken into account to the same degree."
The Council of Trade Unions says the change will make it easier for migrant workers to speak up.
CTU secretary Peter Conway says it has long awaited such a crackdown, and called on the Government to also introduce stronger penalties for employers who breach the Minimum Wage Act.