Bristol police dog handler Paul Nesbit-Bell has been cleared of pushing a triathlete off his cycle, causing him to break his collar bone.

PC Nesbitt-Bell, who has nearly 20 years of service with Avon and Somerset police, said cyclist William Shackcloth banged the side of his truck in a "frenzied attack" as they went on to a roundabout and he parked his vehicle up ahead to ask him why.

The police officer told a Bristol Crown Court jury that when he extended his left arm to the cyclist to get him to stop, Mr Shackcloth wobbled, collided with the kerb and fell into the road.

He insisted: "I made no physical contact with him."

PC Nesbit-Bell, aged 42, of Chipping Sodbury, denied assault occasioning actual bodily harm in September last year and a jury of six men and six women took 10 minutes to unanimously find him not guilty yesterday.

The officer declined to comment as he left court after the hearing.

Retired aerospace engineer Mr Shackcloth, 65, who is a part-time swimming coach and took part in Olympic-distance triathlon events, said that on September 16 last year he was on an end-of-season cycle training session when he was heading towards Yate, on Shire Way, and approaching a roundabout intending to leave it at the second exit for Rodford Way.

He told the court he had had to take evasive action to avoid a van which pulled up to his right and seemed to be trying to use the same piece of road as he was.

Mr Shackcloth said that, after banging on the side of the van and avoiding a collision, he negotiated the roundabout but then saw the truck parked, with its door open and blocking the cycle lane.

He claimed that as he passed the driver, who had got out, raised his hands and, although he neither felt nor saw contact, said he was pushed and lost control.

The jury was told PC Nesbit-Bell had an "exemplary" Army service record before serving as an officer with Avon and Somerset police in a manner described by several colleagues as professional and proper.

He received a chief constable's letter of thanks in 1996 for detaining a suspect after a rooftop chase; a commendation from Avon coroner Paul Forrest in 2002 for trying to save the life of a man found hanging at Blaise Castle and a further police commendation in 2006 for arresting a violent thief while off-duty at Cribbs Causeway.

PC Nesbit-Bell said on the day in question he was driving his Iveco truck, which he used for his part-time business in tree surgery and grass cutting.

He told the jury he was aware of the cyclist and, as they joined the roundabout, the cyclist banged his nearside passenger door "five to six" times and moved his nearside mirror.

PC Nesbit-Bell said he drove on to Rodford Way and parked, with the intention of asking the cyclist why he had banged on his vehicle.

He said: "I held up my left hand and I asked him to stop.

"Mr Shackcloth saw me standing in the road; he got up out of his saddle and increased his speed. He was moving to my left and he began to wobble.

"As he was in line with me, he touched the kerb. He scooted down the kerb and he fell off over his handlebars and fell back into the road. I had no physical contact with him. I didn't push him."

PC Nesbit-Bell said he moved the cyclist and bike from the road and called police after the incident, informing them he was a fellow officer when they arrived at the scene.

He later worked his evening shift policing a football match, he said.