Key Points:

A father has condemned four Whakatane police officers, who have been cleared of assaulting his son.

A Tauranga jury has found Sergeants Keith Parson and Erle Busby, Senior Constable Bruce Laing and Constable John Mills not guilty of assaulting Rawiri Falwasser in the Whakatane cells in October 2006.

The four officers were seen on CCTV using pepper spray and batons on Mr Falwasser.

They argued the level of violence was justified by Mr Falwasser's mental condition and drug use.

His father Charles Falwasser was scathing of the four acquitted officers outside court.

He lashed out at the four accused, calling them "lower than low", but quickly insisted not all police officers should be tarnished by their actions. There were many good police who were welcome at his dinner table, Mr Falwasser said.

"They say you have to forgive. We can do that - it might take a bit of time - but it doesn't mean we have to forget."

However he says there are still members of the police force he regards highly, who he would have over for dinner at anytime.

Charles Falwasser says he is opposed to the judge's move to suppress photos and videos that were part of the evidence.

Outside the Tauranga District Court Susan Hughes QC, who spoke on behalf of the four officers, said they were happy with the verdict.

"We're indeed delighted that justice has been done today and all four of them are very grateful for the considered efforts of the jury," Ms Hughes said.

There were audible gasps of relief from families and supporters of the four officers when the jury forewoman repeatedly responded "not guilty" to the various counts. Some were in tears.

Reaction from the Falwasser family was predominantly surprise and disappointment. One close family member walked out saying "pigs", "no justice" and "bullshit".

Emerging from the courthouse later, Ms Hughes said Sergeant Keith Parsons, Sergeant Earle Busby, Senior Constable Bruce Laing and Constable John Mills would not be speaking to reporters because of general instructions that serving police officers did not speak to the media.

She said the four were "delighted justice has been done" and grateful for the "considered efforts" of the jury.

"There was only ever going to be one outcome and this was it," said Ms Hughes.

Police dealt with difficult situations on a daily basis, she said.

In a statement, Deputy Commissioner Rob Pope said that, with the acquittal verdict now concluding the criminal case, there would need to be consideration of employment processes.

"We will move as quickly as possible."

Mr Pope said an immediate and thorough investigation had been launched as soon as police commanders were made aware of the incident that led to the charges.

The officers involved were stood down and the Independent Police Conduct Authority started a separate investigation.

The allegations made were very serious and the CCTV footage from the Whakatane station formed part of the evidence to establish a prima facie case, he said.

Rawiri Falwasser was said to have been suffering a psychotic episode at the time he refused to be searched, fingerprinted or photographed - which led to the use of batons and pepper spray against him.

He did not want to comment after the verdict.

Mr Falwasser said the tight knit family was disappointed.

They had succeeded in getting justice "if what we saw in court today was justice."

The verdicts did not mean the accused were not guilty but rather that there was "a shadow of doubt in what was presented," said Mr Falwasser.

Twelve peers sat in judgement of the defendants - and that is what justice is - that is the justice system," he said.

His wife, Kihi, said she was "absolutely shocked but not surprised" by the outcome of the trial.

"We are in a black and white world," she said.

The couple was against the suppression by Judge Patrick Treston of the closed circuit television footage of what happened to their son over an eight-hour period at the Whakatane police station 20 months ago. They said it should be shown to the nation.

Judge Treston also declined television and newspaper applications to copy photographs Mr Falwasser took of his son's injuries after he was eventually released from custody.