Ngapuhi leader David Rankin is backing a controversial theory that Maori were not the first people to colonise New Zealand.

However, an expert in Pacific history has labelled the idea as ludicrous and baseless.

University of Auckland associate professor Hugh Laracy said ongoing claims that another culture arrived before Maori were not backed by credible evidence.

"[The theory] has been around for a while but it's been thoroughly disposed of by academic specialists."

One such theory was Spanish inhabited New Zealand first, but Dr Laracy said the Spaniards were not in the Pacific until the 1500s, while Maori arrived between 900 and 1000AD.

"It's logically possible a Spaniard bumped into New Zealand, but there's certainly no clear, historical evidence, but a lot of people have tried to make that case."

Dr Laracy said he heard other ignorant claims from Greeks to aliens landing here first.

"People get a kick out of wild speculation."

However, Rankin said the "academic Taliban" were conspiring to hide the truth.

"If we believe our histories, then we as Maori are not the indigenous people of New Zealand."

Maori stories speak of his ancestors being greeted by a different culture when landing on New Zealand's shores and talk of red-headed, fair-skinned people, he said.

"Who were those people who greeted our wakas and red-headed, fair-skinned people?

"You can't deny your oral history. If we try to as Maori we're actually denying our history."