Two lawyers were awarded more than €400,000 each after a jury in Dublin found they were defamed in a press release issued on behalf of controversial billionaire Denis O’Brien.

Darragh Mackin and Gavin Booth sued over the release issued in October 2016 by PR consultant James Morrissey, which suggested they received payment from the IRA, were dishonourable and were unfit to practise law.

After two hours and 20 minutes of deliberation, the jury of nine men and three women on Friday found that the words complained of meant both lawyers acted for an unlawful organisation, the IRA. They had no other defences to consider.

The jury said the lawyers should be awarded €270,000 each in general damages. This reflects damages for a very serious defamation. According to Supreme Court guidelines a jury should only award more than €300,000 in exceptional cases.

The jury awarded the lawyers €141,750 each in aggravated damages. Justice Tony O’Connor also made an order against O’Brien and Morrissey for their legal costs.

“The press release issued by James Morrissey on behalf of Denis O’Brien advanced serious and entirely baseless defamatory allegations against our clients,” said Johnsons Solicitors on behalf of the two lawyers following the verdict.

The pair are “officers of the court and highly respected human rights lawyers”. The allegations made had no foundation whatsoever.

“Today’s verdict speaks for itself. The jury’s award of substantial damages, together with aggravated damages, delivers a public vindication of our clients’ reputation and professional standing.

“This outcome underscores the gravity of the defamatory allegations and reaffirms that such unfounded attacks on individuals who serve the justice system should not be tolerated.”

The libel action, which was heard in Dublin’s High Court, had its roots in a report on media ownership. Mr Mackin and Mr Booth were credited as co-authors of the report, which was commissioned by Sinn Féin MEP Lynn Boylan.

Mr O’Brien (pictured) had a major stake in Independent News and Media, one of Ireland’s largest mainstream media organisations, at the time the report on media ownership was published.

The press release issued on behalf of Mr O’Brien stated that “Sinn Féin/IRA certainly got the report they paid for”. The jury found this sentence meant the lawyers had acted for an unlawful organisation.

Speaking outside court, Mr Mackin said that it had been “a very difficulty journey to live with very damaging allegations for the past decade”.

The result, he added, was not about “the size of the dog in the fight, it was the size of the fight in the dog”.

He said that human rights lawyers had been killed in the north of Ireland for being aligned with their clients. Mr Mackin said there were “very serious and real-life ramifications to words”.