Police misconduct allegations have surged in recent times, with almost 2000 claims being levelled against staff in the first six months of this year alone.

Official figures reveal alleged cases of misconduct have increased by 21 percent compared to the same period in 2017, bringing the average number of complaints to about 13 per day.

Police Association President Chris Cahill told Newshub the spike is "significant".

"We'd like to know what is the cause behind that," he says.

Data collected by New Zealand Police between January and June this year shows 1329 incidents were reported involving 1808 staff, resulting in 1992 allegations made.

National manager for police professional conduct, Superintendent Anna Jackson, says the organisation sets high professional standards and demands that staff act with integrity.

However she admits the police force is not perfect.

"Despite the best of intentions, individual staff members are human; they and the organisation as a whole don't always get it right," she says.

The top five complaints by category are:

Service failure (706)

Unprofessional behaviour (342)

Use of force on duty (245)

Breach of official conduct (225)

Arrest/Custodial (219)

Wellington District had the largest number of allegations (216), followed by Bay of Plenty (184) and Counties Manukau (183).

The majority of people complained about a failure to investigate, which reflects a stretched workforce, according to the union.

"[Police Association members] don't believe they have the resources to give their communities the service they deserve."

Less than half of the allegations against police have been fully investigated. As of June, 987 cases were closed - with 61 being upheld.

The union believes police officers respect the need for their actions to be scrutinised, but are "frustrated" with the time that process takes.

Mr Cahill says complainants would often prefer a simple apology as opposed to a full-scale investigation.

Police officers are thrown into high-pressure environments and are always faced with split-second decisions, he says.

"They'll be conflict situations, they'll be situations where people are unhappy with police involvements.

"You're always going to get complaints," he says.

Supt Jackson agrees that allegations of misconduct are unavoidable, but says there will be no hesitation to hold officers to account if their conduct is out of line.

Newshub.