National Hunt jockey Robbie Dunne has been found guilty of bullying and harassing fellow rider Bryony Frost over a sustained period.

Dunne could now be facing a ban of up to three years following a British Horseracing Authority (BHA) disciplinary panel ruling that he engaged in "conduct prejudicial to the integrity, proper conduct and good reputation of horse racing by bullying and harassing a fellow jockey".

The panel will now consider its punishment, and release the full written reasons for its finding at a later date after hearing submissions on a penalty from the BHA and Dunne's legal representatives.

The chair of the panel, Brian Barker, told Dunne that they had concluder from the hearing that "a course of deliberate conduct over a significant period of time has been revealed".

Barker added: "This progressed from distasteful targeting to deliberate harassment both on and off the course, including occasional cases of dangerous bullying [on the course].

"We have real concern the weighing room culture is deep rooted and coercive and is not conducive to the good health and development of race-riding."

During the hearing it was revealed that on one occasion he approached Frost following a race at Stratford and, according to Louis Weston representing the BHA, said "words to the effect that you are a f****** whore and you're a dangerous c***. And if you ever f****** murder me [cut me up] like that again, I'll murder you."

The panel was also shown video footage of three races in which Dunne is alleged to have ridden in an intimidating way towards Frost.

He was said to have told Frost after riding at Uttoxeter in August last year that "I'm going to stop you murdering everyone and I'm going to murder you", which was described as being "conduct that is simply unacceptable" by Weston.

Frost told the panel there was "only so much you can take" before she reported Dunne to the BHA.