A political activist arrested for trespassing at the grounds of RTÉ studios has avoided a jail sentence but has been fined €300.

About 50 protesters from various groups had turned up at the gates of the broadcaster in Donnybrook, Dublin 4 to protest about alleged media bias.

Gardaí believed some of them intended to disrupt broadcasting of the Nine News or The Late Late Show, Dublin District Court heard.

Stephen Bennett, 42, of Pearse Green, Sallynoggin, Co Dublin, was found guilty of trespassing with intent to commit an offence, on the night of 31 January last.

He had denied the charge, claiming he was engaging in a peaceful protest at RTÉ.

Judge Bryan Smyth said the fine had to be paid within six months or the defendant would be jailed for five days in default.

Garda Martin Folan told Judge Smyth that a large barrier was erected at the main gates to stop unauthorised people getting into the grounds of RTÉ.

At about 8.30pm, some protesters tried to pull it down and there was a minor scuffle, said Garda Folan.

When they failed they walked along the perimeter fence and Bennett jumped into the grounds of RTÉ and stumbled onto his knees, Garda Folan said.

He also said Bennett resisted as handcuffs were placed on him and the protester was then put in a van before being taken to Donnybrook Garda Station.

In cross-examination he agreed that Bennett, who defended himself in the trial, had not been arrested for pulling at the barrier.

Garda Folan said he did not recall Bennett kneeling or holding a placard when he was arrested.

He also denied that Bennett was first told why he was arrested after he had been handcuffed and placed in garda van.

Garda Inspector Martin McGonnell said the protest involved 40 to 50 people from a number of disparate groups.

Initially it was peaceful but at about 8.30pm some protesters started pulling at a barrier but they were thwarted, he alleged.

Garda Inspector McGonnell said he believed that it became obvious they were trying to disrupt the Nine News or The Late Late Show.

He said the group with Bennett were cautioned not to enter the premises and they moved down the N11 road where the accused launched himself over the wall.

After his arrest other protesters began to block the N11.

When asked if there was a law against interfering with a live broadcast, Inspector McGonnell said the accused was charged with trespassing with intent to commit an offence.

He has known Bennett for a number of years for his involvement in protests outside the Israeli embassy. He said he believed the accused intended to commit a criminal damage offence.

Bennett denied he was not a leader of the group and explained it was like the Occupy Dame Street protesters which did not have leaders.

Video evidence of his arrest was played and showed protesters carrying banners, one of which said: "Ireland says no to media bias".

Bennett, an unemployed father-of-one, told the court that he was using his constitutional rights to protest peacefully and engage in freedom of expression and he argued that the prosecution had not proved he had an intention to commit an offence.

He also asked the judge to note that no other charges to suggest he had acted violently had been brought against him, however, Judge Smyth said he was satisfied the State had proven its case.

Bennett had district court convictions which included criminal damage, violent behaviour in a garda station, motoring and public order offences.