The High Court has ruled that an independent IT expert review materials produced by businessman Sean Gallagher's as part of his action against RTÉ over the 'Tweetgate' incident during the 2011 presidential election campaign.

Ruling on an application by RTÉ to strike out the claim, Mr Justice David Keane said that despite holding that the businessman had failed to make proper discovery of material to RTÉ, the court was not yet halting Mr Gallagher's damages action.

The judge said in order to remedy the situation an independent expert should conduct a review and report on Mr Gallagher's discovery.

The judge added that as part of this review the former presidential candidate should also swear a comprehensive affidavit of discovery.

The case was put back to a date in early July to allow the expert conduct the review.

In his action against RTÉ Mr Gallagher seeks a declaration the October 2011 RTÉ Frontline debate involving the election candidates was deliberately and unfairly edited and presented and directed by RTÉ in order to damage his electoral prospects.

He claims the broadcast was not objective, impartial or fair to his interests.

He is also claiming damages for alleged breach of statutory duty, negligence and misfeasance in public office.

His claim includes a claim for exemplary damages arising from comments allegedly made by broadcaster Pat Kenny in relation to "Tweetgate".

RTÉ denies the claims and also pleads Mr Gallagher damaged his election prospects because of the manner in which he responded to particular assertions.

In its pre-trial application RTÉ sought to have the case halted because Mr Gallagher had failed to comply with orders previously given by the High Court to discover certain material.

The broadcaster wants various materials from Mr Gallagher, including communications via email and documents generated during the course of Mr Gallagher's campaign to be elected president, which it says are relevant to its defence of the claim.

Alternatively, RTÉ sought an order compelling Mr Gallagher to comply in full with his discovery obligations.

Mr Gallagher's lawyers opposed the application.

They argued the businessman had complied with the discovery process and the case against the national broadcaster should be allowed to proceed to a full hearing.

Mr Gallagher's lawyers had proposed the appointment of the independent IT expert and had also offered to indemnify RTÉ in respect of the cost of hiring that person.

In a detailed judgment Mr Justice Keane said Mr Gallagher had failed to make discovery of certain relevant data he holds and failed to make proper discovery of electronically stored information in his possession or power.

While the judge said that he did not find this "default to be wilful or contumelious" he was "driven to the conclusion" it was "negligent."

However the judge added that he did "not think it has yet compromised the prospect of a fair trial to the extent that the justice of the case warrants an order striking out the proceedings".

The judge made several orders which he said was to deal the discovery issues including that the parties appoint an independent expert that specialises in the discovery of electronic material.

The expert, whose fees and expenses must be covered 50-50 by the parties, is to conduct a comprehensive review of materials discovered by Mr Gallagher.

The judge ruled that the expert must be provided with a list of persons who may hold devices on which relevant data or information may be held.

The expert is then to provide a report to both sides' solicitors within four weeks of their appointment.

After he receives the report Mr Gallagher must swear a further consolidated or comprehensive sworn statement on the discovery "as soon as practicable," the Judge also ordered.

All communications between the expert and Mr Gallagher in connection with the review must also be copied to RTÉ, the judge added.

The judge then adjourned the case for 12 weeks to allow these steps to be taken.