The documents contain names, addresses, dates of birth, occupations and contact phone numbers for members of the public. They include details about an "aggressive and hostile" man who was taken to hospital bleeding from both hands. Another entry details a "non-compliant" 15-year-old girl who was taken into custody, and the notebook contains information about a car crash involving a high-ranking academic.
For privacy reasons the Herald has chosen not to identify or contact any of the named individuals.
Dunedin Clutha Waitaki area commander Inspector Jason Guthrie would not be drawn on whether the notebook was stolen or misplaced by the officer. However the Herald understands the investigation centres on whether the notebook was obtained illegally by someone outside the police. It has now been recovered.
"Police confirm that they are conducting a criminal investigation into the circumstances surrounding the disappearance of a police notebook during a search warrant at a North Otago address in August 2014," he said.
Jason Patterson's rural property was being searched when the notebook disappeared. He strongly denied making copies of the pages and told the Herald he would not breach anyone's privacy.
Mr Patterson said after the search police told him a notebook was missing and returned two days later to see if it had surfaced.
He said he eventually found it under a dog kennel when he returned from holiday two months later.
Mr Patterson posted it to Shannon Parker of civilian watchdog group New Zealand Police Conduct Association, who lives in Northland, who arranged to return it to Whangarei police. She said she did not make any copies.
Lost property
*In 2008 police left a camera containing crime scene images at a Lower Hutt house during a search for drugs.
*In 2009 a police manual with details on an investigation was left on a table at a gang member's house during a search warrant.
*In 2012 sensitive information about rape and sexual assault victims went missing after the ACC contractor who was entrusted with the documents packed them in a suitcase - which was stolen from a bus.