Three Supreme Court judges will meet next week to consider whether to hear a "leapfrog" appeal by the State against an important ruling in favour of convicted murderer Graham Dwyer.
The High Court ruling, given in judicial review proceedings by Dwyer concerning the use of mobile phone data at his trial, forms part of Dwyer's bid to overturn his conviction for the murder of childcare worker Elaine O'Hara.
A leapfrog appeal is an appeal directly to the Supreme Court instead of taking the normal appeal route to the Court of Appeal.
The Constitution provides the Supreme Court can hear an appeal directly from a High Court decision if it considers the matter raises a point of law of general public importance or an appeal is necessary in the interests of justice.
On Monday, three Supreme Court judges - the Chief Justice Mr Justice Frank Clarke, Mr Justice John MacMenamin and Ms Justice Iseult O'Malley - will meet in chambers to consider the State's application.
It is understood Dwyer is not opposing the court hearing an appeal.
The judges' decision on whether or not to hear a leapfrog appeal will be issued via a published written determination on a later date.
The State is appealing against Mr Justice Tony O'Connor's High Court finding that part of the State's data retention laws concerning information generated by telephones contravenes EU law and provides for an indiscriminate data retention regime.
As well as being an important ruling in relation to Dwyer's appeal against conviction, a date for which has yet to be fixed, the State says it has major implications in relation to the authorities' ability to retain, access and use information generated by mobile phones in the investigation of serious criminal activities.
Last January, Mr Justice O'Connor granted Dwyer a declaration that Section 6.1(a) of the Communications (Retention of Data) Act 2011, which allows data generated by mobile phone to be retained and accessed, was inconsistent with Articles 7, 8 and 52.1 of the European Charter of Fundamental Rights.
Noting the State intended to appeal, the judge said his ruling should not be used as a reason for retained telephony data to be destroyed.
Dwyer, who denies killing Ms O'Hara, had claimed that data gathered from his phone, under the 2011 Act, should not have been used at his 2015 trial before the Central Criminal Court.
The data, generated by Dwyer's work phone, placed the phone at specific places at particular times and dates.
It was used to link Dwyer to another mobile phone which, the prosecution argued, he had acquired and which he had used to contact Ms O'Hara, with whom he had had an affair.
The use of the data, Dwyer claimed, breached his rights, including to privacy, under the Constitution, EU Charter and the European Convention on Human Rights.
Dwyer's lawyers argued the Act was introduced to give effect to a 2006 EU directive concerning the retention and use of data. The European Court of Justice (ECJ) found in 2014 that the directive was invalid and that position was further strengthened in subsequent rulings by that court in 2016.
Dwyer claimed the 2011 Act suffered from the same flaws identified by the ECJ.
Mr Justice O'Connor held the 2011 Act provides for an indiscriminate retention regime and said the ECJ had found such regimes are prohibited under articles of the European Charter.
He also found Garda practices of applying for and obtaining mobile phone data were not enough to satisfy the decisions of the European courts in regard to access.
The sections of the 2011 Act concerning access to retained data contravene EU law and the European Court of Human Rights because there was no prior review by a court of administrative authority for access to telephony data, he ruled.