A Police Ombudsman investigation has cleared a police officer of using excessive force during the St Patrick's Day parade in Kilrea in 2010, but has also concluded that his actions heightened tensions and led to police resources being stretched.

The policeman (Officer A) was among a group of three officers who went to speak to a group of men, three of whom appeared drunk and were shouting Republican slogans.

An altercation between Officer A and one of the men (Man A) ensued, during which Officer A was punched in the face by Man A. Officer A retaliated with a punch to the face before arresting Man A for a number of offences, including assaulting police, disorderly behaviour and resisting arrest.

A number of onlookers intervened during the arrest, and additional officers were required to quell the disorder. CS Spray was used by police and a number of other members of the public were also arrested.

After the arrests, the two officers who were with Officer A during the incident, expressed concern to their supervisor that Officer A's actions had been heavy-handed and over-zealous. They said his insistence on obtaining personal details from Man A had incited the crowd, stretched police resources and placed officers in danger.

Another police officer (Officer E) also expressed concern that Officer A overreacted at Coleraine Police Station, where Man A was taken after his arrest.

Man A had been verbally abusive on the way from Kilrea to Coleraine, and became violent on his arrival at the station. He was placed in limb restraints but began spitting as he was being taken to a cell. Officer A pulled Man A's hood over his face to prevent this.

When officers subsequently attempted to search Man A in his cell, Officer A was restraining Man A's upper body and tried to remove his hood to facilitate the search.

Officer E said he placed his hand on Officer A's back during this incident and told him to calm down, and later spoke to him to tell him that he believed his actions during the cell search had been overly aggressive and heavy-handed.

The concerns raised by Officer A's colleagues in Kilrea, and by Officer E at Coleraine Police Station, were subsequently referred by the PSNI to the Police Ombudsman for independent investigation.

During their investigation, Police Ombudsman investigators interviewed police and civilian witnesses who had been present during Man A's arrest, and issued a media appeal in a bid to identify additional witnesses.

They also checked for CCTV footage of the arrest. None was available, but they did secure footage of the subsequent disorder from a police evidence gathering team which had been operating in the area.

Investigators also retrieved and analysed recordings of police radio transmissions relating to the incident. These established that, following Man A's arrest, Officer A had made a transmission stating that Man A "punched me in the face and he got the same back."

In addition, all the officers who had made adverse comment about Officer A's actions were interviewed.

CCTV footage of the incident in the cell at Coleraine police station was also examined, and this led Police Ombudsman investigators to conclude that none of the officers involved, including Officer A, had used excessive force against Man A.

When interviewed, Officer A denied that his actions, either at the parade or in the cell, had been overly-aggressive. He said that he needed to make a prosecution report, and when Man A refused to give his details he had no choice other than to arrest him.

Officer A accepted that his emotions had run high given that he was assaulted and threatened by Man A, but maintained that he had acted professionally at all times. He said the punch to Man A had been an instinctive reaction to being punched himself.

Having reviewed the evidence, the Police Ombudsman, Al Hutchinson, concluded that Officer A was correct to approach Man A and others who were drinking on the street.

However, he also found that Officer A's persistence in requiring the personal details of Man A had aggravated an already tense situation. He said Officer A had failed to properly take account of the crowd dynamic around him, and police resources had been stretched in the subsequent disorder.

"A more considered approach would have been to conduct enquiries at a later date in order to identify Man A and progress the matter accordingly," said Mr Hutchinson.

In relation to the allegations of assault against Officer A, Mr Hutchinson concluded that Officer A had not used excessive force, either during the initial incident at Kilrea, nor at Coleraine police station.

The Police Ombudsman recommended that Officer A should appear before a disciplinary hearing in respect of his handling of the initial incident in Kilrea. The disciplinary panel found the charges against Officer A not proven.

In addition, the Public Prosecution Service also directed that Officer A should not face prosecution in relation to the allegations of assault which had been made against him.