On Sunday, Prime Minister Jacinda Ardern delivered a formal apology for racial profiling practices in support of immigration policies half a century ago.

The "Dawn Raids" of the 1970s saw police target homes of Pacific immigrants searching for visa overstayers.

Studies have since proved Pacific communities had similar numbers of overstayers than visa holders from the United Kingdom and United States, who did not attract the same police attention or brutality.

Ms Ardern's apology, in a three-hour ceremony with many traditional practices of NZ and the Pacific, was deeply appreciated.

"Thank you for listening to the voices, as much as the silence, of the people most deeply affected," Alec Toleafoa, of resistance group the Polynesian Panthers, said.

"You have the heartfelt thanks of the Polynesian Panthers for this incredible moment."

Hundreds watched inside Auckland Town Hall and thousands more watched broadcasts in their homes across NZ and the Pacific.

The service began with an arresting audio montage of sounds from the era featuring police dogs, screams, singing.

In a gesture that moved many, Ms Ardern was covered in by a weaved mat, a symbol of ritual apology known as ifoga, before giving her apology.

"I stand on behalf of the New Zealand government to offer a formal and unreserved apology to Pacific communities for the discriminatory implementation of the immigration laws of the 1970s that led to the events of the dawn raids," she said, in a 10-minute address.

Tongan Princess Mele Siu'ilikutapu Kalaniuvaulu Fotofili was one of several community leaders to respond during the ceremony.

"We acknowledge with deep gratitude the gifts you are presenting ... good gestures," she said.

"The beginning of a caring, closer and better relationships between your government ... and our pacific peoples at large."

Ms Siu'ilikutapu then turned to the thorny issue of reparations through immigration reform and amnesties for modern-day overstayers.

"(The apology) could be better and complete should the government promptly respond to the immigration related needs of our community," she said, to huge applause.

"Let us make Aotearoa our home."

Ms Ardern committed to educational scholarships for Pacific students in NZ and the region, and new resources to teach the history of the Dawn Raids in schools - but wouldn't make it a compulsory part of the curriculum.

University of Auckland senior research fellow Melani Anae told Radio NZ that wasn't enough.

"All they were to us were gestures. They have to go much further than they do before we can expect real change," Dr Anae said.

"What we wanted is that it was compulsory for all New Zealanders to learn about it."

Watching at a live site across Auckland, Soana Aleva told Tagata Pasifika she felt lucky to see the day where an apology was given.

"Some of them took it to the grave. I'm glad I was here to see it live," she said.

Australian Associated Press