Protesters have vowed to continue their fight against a Midland hunt after an anti-hunt campaigner was cleared of killing a hunt supporter with the blade of a gyrocopter.

As animal rights enthusiast Bryan Griffiths walked free from Birmingham Crown Court cleared of the manslaughter of hunt supporter Trevor Morse, his colleagues said the war they had waged against the Warwickshire Hunt was far from over.

Tensions between the hunt and a group of protesters had been building long before the death of Mr Morse at Long Marston airfield last March, it has been revealed.

For months anti-hunt groups had followed the Warwickshire Hunt across the countryside, taking video footage and piloting a gyrocopter as part of a plan to monitor if it was hunting legally.

Anti-hunt groups told the Birmingham Post they warned police months before the death that the atmosphere had become “very unpleasant” between the rival groups and Warwickshire Hunt had made complaints to the Civil Aviation Authority about the use of the gyrocopter, which would fly over the riders and their horses.

The battle in the country lanes of Warwickshire often saw anti-hunt protesters being monitored themselves by supporters of the hunt.

Police said there had been assaults, public order offences and cases of obstruction involving incidents surrounding the Warwickshire Hunt in the past.

Details of the clashes came out during the trial of Mr Griffiths, who was found not guilty of manslaughter by gross negligence by a 10-2 majority.

Mr Griffiths, of Wiltshire Close, Bedworth, had been monitoring the hunt from the air on March 9, with a passenger in his two-seater gyrocopter.

He landed at the airfield to refuel and Mr Morse, 48, stood in his path, refusing to move out of the way. Mr Griffiths went towards him in the gyrocopter, cleaving his head “from top to bottom” with the blade.

Mr Morse’s death was caught on camera by Peter Bunce, the man who had taken fuel to the airfield.

Judge Mrs Justice Slade said there had been simmering tensions between the two groups leading up to the death of Mr Morse.

Mr Griffiths had offered his piloting expertise to anti-hunting campaigners during a meeting of the League Against Cruel Sports in Coventry in 2006.

In 2007 he rented a helicopter for monitoring purposes. A member of the Warwickshire Hunt reported him in the same year to the Civil Aviation Authority for disturbing livestock and horses.

He signed an undertaking not to fly below 1,000 feet over future hunts.