Neglect of duty, and language and attitude problems rank among the most common complaints to the Independent Police Conduct Authority (IPCA).
The body, formerly the Police Complaints Authority, in its first annual report presented to Parliament this week, revealed that it had received 3778 complaints, which the report states is "believed to be the highest in the authority's 20-year history".
Of those complaints, 2696 made by 1690 complainants were accepted for investigation in the year to June 30 - including 11 which related to deaths.
Topping the list of 34 listed areas of concern, with 334 complaints, was "neglect of duty", or "failure" by police, which includes complaints about inadequate investigation, failure to provide medical assistance, and to provide food and water to complainants.
The second most common topic of complaints was police practices and procedures, with 332 complaints. The attitude and language of officers caused 316 complaints, and use of physical force prompted 222.
The IPCA, which police are required to notify of any death or serious bodily harm resulting from their actions, received 11 reports of deaths, including one suicide, and 48 reports of serious bodily harm.
Deaths include the police shooting of Christchurch man Stephen Bellingham, 37, in September last year and fatal police pursuits.
A total of 223 complaints were upheld, 18 were partially upheld, 687 were not upheld, 621 not pursued and 539 were referred to police for resolution with the complainant.
The authority's nine investigators were involved in 350 investigations of complaints - some of which were also investigated by police for criminal charges and internal disciplinary matters.
The largest number of complaints came from the Waitemata police district, which had 317 complaints, followed by Wellington and Auckland which each had 309, then Counties Manukau, with 265.
The IPCA was reformed from the Police Complaints Authority in November last year to increase transparency and accountability after the commission of inquiry into police conduct.
IPCA complaints 2007-2008:
* 3778 complaints - 2696 accepted, 2006-07: 3526 complaints, 3093 accepted for investigation.
* The 2696 accepted complaints stem from 1690 complainants.
* 223 upheld.
* 18 partially upheld.
* 687 not upheld.
* 621 not pursued.
* 539 referred to police for resolution with complainant.