A new-fangled immigration scheme thought to be exploiting people is calling for an imperative investigation in the Chinese and Filipino migrant communities.

In order to obtain New Zealand permanent residence, Immigrants are entering agreements with employers to pay their own taxes and wages and the "scheme" even has its own name - PYO (pay your own).

Immigration New Zealand says it is investigating a case where such a scheme has allegedly been used to help a migrant to gain residency, and the agency is asking others with information about the scam to come forward.

Employment advocates say the practice is rampant and has been going on for years, with possibly hundreds gaining residence by paying their own way to meet immigration requirements for skilled migration.

PYO or 'pay your own' deals have potential migrants paying their own wages and tax, in return for support for their residency applications.

National Distribution Union spokesman Dennis Maga says there should be an investigation into some building businesses, in particular. He says Immigration New Zealand does not move against anyone until it is presented with a concrete case. Mr. Maga says it is hard to know how common the scam is, because arrangements are often kept within migrant communities.

Mr. Maga says the scam needs to be addressed now before it becomes systemic.