The release of New Zealand's largest ever crime survey has revealed 77 percent of crimes go unreported.

Less than a quarter of all crime was reported to police over a 12 month period.

More than 8000 people were interviewed between March and October 2018 and asked about any crime they had experienced over the past year.

"This survey is a vital piece of information to help us understand the true volume and nature of crime in New Zealand, and who it affects," said Ministry of Justice chief executive Andrew Kibblewhite.

Many people did not even realise a crime had been committed against them.

"They thought what happened was just normal behaviour," said Ministry of Justice manager of research and evaluation, James Swindells.

"This information is extremely valuable for the Ministry, police, corrections, Oranga Tamariki and many other Government agencies as we look at reducing crime and its impact."

Seventy-one percent of New Zealanders said they have not experienced crime within the last year.

The 148-page report is the first of three annual surveys which will cost $3.7 million.

Interviews for the second report in 2020 are already underway.

Newshub.