Three Mayo men are suing for damages over alleged garda brutality at a Shell to Sea protest eight years ago.
Patrick Coyle, and brothers Patrick and Martin O'Donnell, claim they were assaulted at Bellanaboy bridge on January 19, 2007.
It is the men's case that gardaí displayed brutality and indiscipline during a protest outside the Shell oil refinery at Bellanaboy.
They claim Patrick Coyle was punched in the face and struck on the back of the head while trying to stop another demonstrator being pulled from the line of protesters by gardaí.
It is also alleged that when fishermen Patrick and Martin O'Donnell came to his assistance, they were also assaulted by gardaí without any provocation.
Opening the case, their barrister Michael O'Higgins told the jury gardaí have a video of the protest but that there is an unexplained seven-minute gap at the time the alleged assaults took place.
The jury has been told gardaí will dispute the men's claims and it will be for them to decide who were the aggressors.