High Court dismisses discovery inspection request where litigation privilege is not overridden by data protection law.

THE HIGH COURT

[2026] IEHC 424

[Record No. 2024/2868 P]

BETWEEN

GILLIAN MCDONALD

PLAINTIFF

-AND-

HEALTH SERVICE EXECUTIVE

DEFENDANT

-AND-

QUEST DIAGNOSTICS INCORPORATED

THIRD PARTY

Ex tempore ruling of Mr Justice Paul Coffey delivered on the 15th day of April 2026

1. What falls for determination is a discrete procedural issue of inspection of documents arising within the Plaintiff’s application for discovery, which remains pending before this Court. Its resolution does not dispose of the discovery application as a whole, nor does it determine any potential substantive issues, not yet pleaded, arising from concerns raised by the Plaintiff relating to possible breaches of data protection law, privacy rights, or professional obligations.

2. The issue arises because, prior to delivering a replying affidavit in the discovery application, the Plaintiff sought inspection of two documents over which the Defendant asserts litigation privilege. The Plaintiff accepts that both documents attract litigation privilege but contends that inspection is nonetheless required for a limited regulatory purpose.

3. The sole question for determination is therefore whether, having regard to the concessions made by the Plaintiff, the Court may order inspection of those two documents prior to hearing the discovery application.

4. The discovery application arose following the inadvertent disclosure by the defendant on 2 March 2026 of a letter dated 3 September 2025, authored by the Plaintiff’s former treating clinician at the National Maternity Hospital. It is common case that the letter refers to the Plaintiff’s personal medical data and that it was sent for a non-clinical purpose to a claims co-ordinator employed at that hospital.

5. That disclosure prompted concerns on the Plaintiff’s part as to the circumstances in which her medical data had been requested and used, and led to the bringing of the discovery motion.

6. Affidavits were exchanged in the application, including a Grounding Affidavit on behalf of the Plaintiff and a Replying Affidavit on behalf of the Defendant. It was during that exchange that the present issue arose.

7. In her Grounding Affidavit, the Plaintiff proceeds on the assumption that the letter of 3 September 2025 was generated at a time when no allegation of wrongdoing had been made against the treating clinician.

8. On that footing, the Plaintiff inferred that the request for, and use of, her medical information could only have occurred for a non‑clinical and therefore impermissible purpose. That assumption shaped both the concerns articulated and the breadth of discovery initially sought.

9. In its Replying Affidavit, the Defendant advances a materially different factual account. It contends that, in the context of separate and distinct indemnity proceedings, the Third Party made allegations against the treating clinician, that those allegations arose only in without‑prejudice correspondence, and that the letter of 3 September 2025 was generated for the purpose of responding to those allegations in the defence of litigation.

10. Before delivering a Replying Affidavit, the Plaintiff sought inspection of the entire chain of correspondence relied upon by the Defendant to explain the background to the letter of 3 September 2025 and the assertion of litigation privilege. At the oral hearing the Plaintiff’s application was narrowed to a letter dated 9 January 2025 and an email dated 25 June 2025.

11. This ruling is confined exclusively to whether the Plaintiff is entitled to inspection of those two documents.

12. The Plaintiff accepted that both documents are litigation communications that prima facie attract litigation privilege, and further accepted the Defendant’s sworn description of their background and purpose. By necessary implication, the Plaintiff accepted that the request for her medical information was made in the course of and for the purpose of defending litigation.

13. The Plaintiff also accepted that she is aware of the use made of her medical information by reason of the inadvertent disclosure of the letter dated 3 September 2025.

14. Notwithstanding those concessions, senior counsel on behalf of the Plaintiff submitted that litigation privilege is not absolute and must be strictly construed such that the concessions made were not determinative of the issue before the Court. Relying on the letter of 3 September 2025 as suggesting a potential breach of Article 14 of the General Data Protection Regulation (‘GDPR’), it was argued that notwithstanding the Plaintiff’s knowledge of the contents and purpose of the letter, inspection of the two documents was nonetheless necessary to explore the legitimacy of the request for the Plaintiff’s personal data under data protection law having regard to Article 23 GDPR. Article 23 permits Member States to restrict specified rights and obligations under the Regulation, provided that any such restriction is necessary and proportionate to safeguard the interests identified in that provision. It was accepted that this application was being made in circumstances where no breach of data protection law, privacy rights, or duty of confidentiality on the part of the clinician has been pleaded.

15. The Defendant submitted that, having regard to the Plaintiff’s concessions, the application could not succeed on the basis that section 162 of the Data Protection Act 2018 expressly preserves legal professional privilege and that data protection law does not override or qualify it.

16. I accept the Defendant’s submission that litigation privilege applies and is determinative of the issue before the Court. While it is not absolute and is subject to recognised exceptions, no such exception arises here.

17. The Plaintiff’s residual contention, that privileged correspondence should be disclosed in order to explore the legitimacy of a request she accepts was properly made for the purposes of litigation, cannot be reconciled with the nature or function of litigation privilege. Privilege exists precisely to protect communications made for the purpose of defending legal proceedings from adversarial scrutiny, and it would be deprived of any practical content if it could be displaced whenever a party sought access in order to investigate whether a statutory or regulatory claim might be formulated. Where, as here, the Plaintiff accepts both that the requests were made for the purposes of litigation and that the correspondence is properly protected by litigation privilege, neither Article 14 GDPR nor any restriction mechanism under Article 23 GDPR provides a basis for compelling disclosure. In the absence of any pleaded breach capable of engaging a recognised exception, the Court has no power to order inspection or disclosure of the privileged material.

18. Questions of necessity and proportionality under Article 23 GDPR do not arise for case‑by‑case determination by the Court in the context of an interlocutory application for discovery. Rather, those requirements are addressed at the level of legislative choice, in the adoption of legislative measures restricting certain GDPR rights and obligations. In Irish law, section 162 of the Data Protection Act 2018 is such a measure, and expressly preserves legal professional privilege and precludes the Court from compelling disclosure of privileged material for the purpose of scrutinising the legitimacy of litigation‑driven requests.

19. Nothing in this ruling determines whether any issues under data protection law, privacy, or professional obligations may arise if properly pleaded.

20. Accordingly, within the discovery application, the Defendant’s claim to litigation privilege over the letter dated 9 January 2025 and the email dated 25 June 2025 is upheld, and the Plaintiff’s interim application, as narrowed at oral hearing, is refused.