A Queensland police unit on the Gold Coast generated dozens of brutality complaints and a longstanding reputation among colleagues for excessive force before several of its members were publicly exposed in a leaked video.

The failed prosecution of former police officer Rick Flori over the leak opened up former members of so-called Surfers Paradise "Team Two" to interrogation over their disciplinary records, which revealed internal investigations of 21 allegations of serious misconduct.

Team Two was one of a number of patrol units operating out of Surfers Paradise police, each with a membership of 12 to 15 officers at any one time.

The ABC can reveal there were at least 21 other complaints of excessive force against another two officers within Team Two in the years leading up to the unjustified assault of Noa Begic in the police station car park in January 2012.

Mr Flori was cleared over leaking police video in February this year. ( ABC News: Josh Robertson )

A Police Ethical Standards Command (ESC) report from 2010, obtained by the ABC, noted the "inordinately large number of excessive force allegations", with ESC issuing a "medium-level warning" to senior Gold Coast police about one officer.

However, it said "no adverse inference can or should be drawn" against the officers because the complaints were not substantiated, and Surfers Paradise was a "volatile" environment.

Corruption watchdog began 'profile' of police unit

But Team Two's overall complaints record prompted the then-Crime and Misconduct Commission (CMC) to "profile" the unit, Mr Flori said.

"Because of the significantly larger number of complaints that team had, not as an individual as such, but a team as a whole … they actually profiled that team prior to the Begic arrest," he told the ABC.

"They had been under scrutiny well before this and relatively little or no action was taken to curb their behaviour."

Two other former Gold Coast officers said team two had a reputation for using unjustified force in arrests and their complaint rate dwarfed other teams.

A spokesman for the CMC's successor, the Crime and Corruption Commission (CCC), said they would "neither confirm nor deny" the agency profiled Team Two.

Internal investigators found the assault against Mr Begic was unjustified and initially covered up.

But in a six-year saga that proved to be a public relations disaster for police, the only officer charged was Mr Flori, for leaking video evidence to the media.

Officer under investigation multiple times

Former senior sergeant David 'Joacho' Joachim, who was in charge at the scene of Mr Begic's assault, was a previous Team Two leader.

Mr Joachim has been investigated eight times by the Police Ethical Standards Command. ( ABC News )

He was investigated eight times by the ESC, including for six alleged assaults on prisoners in custody.

Two of these came in the weeks after Mr Begic's arrest, when he allegedly punched a handcuffed prisoner in the face three times and hit another with handcuffs while threatening to beat him "to a pulp".

He was also investigated in 2009 for alleged corrupt conduct in helping security guards cover up an incident, and in 2007 for responding to an excessive force complaint by charging the person with obstructing police.

In Mr Flori's trial in the Southport District Court last month, Mr Joachim said he could not recall any details of the incidents that prompted complaints or the investigations.

But he agreed none of them were substantiated and he was never charged for anything.

Joachim also under alleged corruption probe in NSW

The Flori trial also revealed that when he was a detective in New South Wales, Mr Joachim was investigated for alleged corruption over a shooting investigation, shortly before he resigned in 1988.

A 2001 Police Integrity Commission report criticised Mr Joachim for being too friendly with a person of interest, and giving a misleading statement in a follow-up investigation in 1996 after he became a Queensland police officer.

The inquiry cleared Mr Joachim of any criminal conduct but noted he eluded disciplinary action because he was no longer a New South Wales officer.

Mr Joachim washed away a pool of Mr Begic's blood and was involved in the struggle on camera but denied seeing an assault, even when confronted with video evidence during Mr Flori's trial.

The court heard that Mr Joachim had reported the violent incident to two inspectors at Surfers Paradise station, but had not told them he was physically involved.

Sorry, this video has expired CCTV vision of Noa Begic being arrested by Queensland police officers in 2012

He told the inspectors he had investigated the matter by viewing the CCTV footage — together with Mr Begic's assailant Ben Lamb and fellow officer Robert Johnston — and found the force was "proportionate".

Mr Joachim also had not disclosed his role to Mr Begic when he visited him in the watch house to see if he wanted to file an assault complaint.

His superiors had not watched the video until Mr Begic filed a complaint a week later.

Inspector Matt Rosevear agreed in court with Mr Flori's lawyer that on watching the footage, he saw a "blindingly obvious potential issue around excessive use of force".

Mr Joachim had told Mr Flori's trial he had a family link to Queensland Police Commissioner Ian Stewart, who was "my brother-in-law's brother".

Commissioner Stewart told media after the trial he had declared his "conflict of interest" and played no role in the investigation.

Mr Joachim and other officers in court maintained the assault was justified because Mr Begic, who was handcuffed and lying prone on the ground, had been "violently resisting arrest".

Police alleged he made offensive comments to passing officers but Mr Begic maintained he was singing a Rage Against the Machine song.

Officer admits force during arrest was 'totally excessive'

In footage of his arrest shown to the District Court, Mr Begic appeared compliant.

This included his approach to the police station carpark, which one officer, then-constable Johnston, admitted was at odds with his account that an agitated Mr Begic had been "jumping around like a freaking Zulu person".

While colleagues maintained the force was appropriate, then-senior constable Lamb, who kneed Mr Begic and punched him six times in the head — in part because he thought he was a Maori and thus likely to be strong — admitted to the court his force was "totally excessive".

"This was a clanger of a day for me," he said.

Mr Lamb said most of the six previous complaints lodged against him in less than two years were "nonsense", although he could not recall details of any of the incidents.

They included allegations that he punched two other handcuffed prisoners in the face, causing major teeth damage to one and allegedly telling him: "You boys aren't planning on making any complaints, are you?"

Mr Lamb was also investigated by the CCC for alleged corruption in 2011 for failing to take action against a person for assault.

No allegations were substantiated, but he was given managerial guidance for striking and pushing a prisoner in custody, causing him to fall against a wall.

Mr Johnston, whom Mr Begic accused of punching him in the head, was cleared of wrongdoing.

Officer investigated over 'choking' arrest

Sorry, this video has expired CCTV vision of arrest of Kristian Puru in 2015

But the court heard Mr Johnston was again investigated in 2015 for violently choking a teenager and seizing a phone he used to film the arrest of his cousin, Kristian Puru.

A magistrate at the time criticised what she found was an unjustified assault by police in the arrest, which resulted in legal costs being awarded to Mr Puru, but no disciplinary action.

Mr Flori's trial heard Mr Johnston was twice chastised for racial abuse, including of one person he allegedly punched in the face and called a "n*****".

The trial also revealed Mr Johnston had quit the force in February 2017 while under investigation for stealing drugs from a raid, assisting prostitution, illegally accessing the police database 900 times, including to gain contact information to stalk his former partner, and lying to ESC investigators.

Mr Johnston twice refused to answer questions in court about several of these allegations to avoid incriminating himself.

ESC investigators maintained in court that no police could be charged over Mr Begic's assault because he withdrew his criminal complaint, separately receiving a confidential payout.

Police disciplinary system is 'broken'

However legal experts, including former NSW director of public prosecutions Nick Cowdery, said a case could proceed on video evidence and Mr Begic's original statement.

"There might be enough evidence [from video alone] to create a reasonable prospect of conviction — it's quite possible," Mr Cowdery said.

Former Queensland police prosecutor and inspector Dominic McHugh said the police disciplinary system was "broken".

Mr McHugh said the police disciplinary system was "broken". ( ABC News )

"It would appear to me that the only reason they avoided criminal charges was because of a culture or an attitude on the part of people within the service to protect their own, or to keep things closeted, or to deal with things quietly, without embarrassing," Mr McHugh said.

Fitzgerald inquiry whistleblower and former ICAC staffer Nigel Powell said the decision to prosecute Mr Flori but not others was a failure of police leadership.

"Do I want to send a message that if you beat a chained, defenceless prisoner for no reason, you are going to be prosecuted … or do I want to send the message: 'Do not embarrass us?'," Mr Powell said.

Flori 'absolutely' vindicated over leaking video

ESC finished its investigation by December 2012, finding a case for disciplinary action against Mr Lamb for excessive force and Mr Joachim for failing to report.

But the report sat with senior police for a year until Mr Joachim retired, just in time to qualify for higher superannuation as a senior sergeant, and also to avoid disciplinary action.

The CMC, which had been publicly calling for police to promptly resolve the matter, was not told about this for another eight months.

Mr Lamb was given "suspended dismissal", which the CMC unsuccessfully challenged in court as a false sanction.

He remains an officer on the Gold Coast.

Mr Flori's defence said he had not had a vendetta but instead wanted to expose misconduct. ( AAP: Dave Hunt )

Mr Flori said the outcome "absolutely" vindicated his decision to leak while an internal investigation was underway.

He said the final straw was a sergeant's meeting the day the investigation began, in which "the discussion revolved around the officers involved being 'looked after', it would be fine, that it was 'covered'".

"The result is really as was predicted — the officers suffered no consequences essentially for their actions," Mr Flori said.

"It's a disgrace and it's the way it's gone on for a long time."

Both Mr Lamb and Mr Joachim have declined to comment, while Mr Johnston could not be reached by the ABC.

Commissioner Stewart declined an interview request, but a spokesman said the public could have "confidence in internal police investigations".