Internet Explorer 11 (IE11) is not supported. For the best experience please open using Chrome, Firefox, Safari or MS Edge


An appeal in the case of Dwyer v Commissioner of An Garda Síochána & Others[1] was referred by the Irish Supreme Court to the European courts for clarification on the EU-law aspects of the appeal. The appeal arose from a challenge to the validity of certain provisions of the Communications (Retention of Data) Act 2011. The applicant had been convicted of murder, in a case where mobile phone data evidence was a central part of the prosecution. He argued that the 2011 Act was introduced to give effect to an EU Directive, the scope of which was later significantly curtailed by the European Court, thereby interfering with his rights under EU law.


The Supreme Court sought clarification on the following areas:

  1. Whether a system of universal retention of data is never permissible, no matter how stringent the regime for accessing that data

  2. The criteria for assessing whether the regime for accessing the data is sufficiently independent and robust

  3. Whether a national court, in finding the national law to be incompatible with EU law, can regard the incompatibility to be prospective only

Advocate General Ruling

The ECJ is assisted by Advocates General, who provide independent legal opinions to the Court. Advocate General Campos Sánchez-Bordona of Spain delivered an opinion to the Court on 18 November 2021. His opinion sets out a detailed analysis of the legal issues. His view was that the existing caselaw provides sufficient clarity with which to address the queries raised by the Supreme Court. He distinguishes between the retention of traffic and location data to guard against threats to national security, as opposed to its’ use to combat serious crime. He also believed that the invalidity should apply to past and future cases.


Although a decision from the ECJ is now awaited, the opinion of the Advocate General will undoubtedly be influential. Upon receipt of a ruling from the ECJ, the Supreme Court can make a final determination in the appeal. That determination will be highly relevant to Mr Dwyer’s conviction.

However, more broadly it is likely to be closely observed by prosecution and defence lawyers in cases which involve mobile, traffic and location data. The status of convictions which relied heavily of evidence obtained on foot of the 2011 Act will also be scrutinised.

There remains an element of uncertainty in this area for now, please don’t hesitate to contact Brian Horkan to discuss the implications in more depth.

The content of this article is provided for information purposes only and does not constitute legal or other advice.

[1] [2019] IEHC 48; IESC 2019/18

Share this: