Allegations of police targeting Maori youths and improperly obtaining DNA samples may end up before the Independent Police Conduct Authority.

Maori Party MP Hone Harawira yesterday stood by comments comparing police actions to "Nazi-style tactics" in persuading Maori youths to give DNA samples.

He said he would support youths and their families if they wanted to lay formal complaints with the authority, and they were working through that option.

This week Mr Harawira said he knew of cases where police had conned youths into providing DNA samples.

"One young Maori told me the police wanted the sample because one of their relatives might be known to police. Another told me the police wanted the sample in case the rangatahi [youth] got killed and the police needed to identify them.

"All of this is completely outside the guidelines, and I am warning police to drop these Nazi-style tactics immediately."

Criminal lawyer Graeme Newell lent support to Mr Harawira yesterday, saying he knew of a case where a police officer had offered a boy a cigarette in return for a DNA sample.

Police Minister Judith Collins said she was not aware of any improper behaviour, and encouraged Mr Harawira to lay a complaint through the proper channels.

But she said the comments about Nazi-style tactics were "offensive", "unfortunate" and "not New Zealand police".

Mr Harawira yesterday stood by his comments.

"The Nazis were noted for the use of cranial studies, bone structure, blood tests, etcetera to prove their beliefs to backstop their biological racism. If the police in this country, if they continue to do what they're doing in an illegal fashion, they're pretty much following the same path.

"In the 1970s they were fingerprinting rangatahi Maori, like me, without permission.

"They were taking blood tests from young Maori in the 1970s and 1980s without permission.

"So when I tell you that the police [are] going after DNA without permission, I am absolutely certain that I'm right about it."

He said he had been in contact with half a dozen families and youths from inside and outside his Northland electorate.

"I bet you as a result of my asking these questions, others will surface."

Voluntary DNA samples for 14- to 17-year-olds can be taken only with the consent of the suspect and a parent.

Legislation to take effect this year will not change that, but will allow the taking of DNA samples from people whom police intend to charge with a relevant offence.

Mr Harawira advised all youths to refuse to give DNA samples.

"Unless the police have a court directive, they should just straight out say no."

He said police had not forced youths to give DNA samples, but had improperly persuaded them.