FIFTH SECTIONCASE OF KOSTENKO v. UKRAINE(Application no. 45800/21)      JUDGMENT STRASBOURG11 December 2025  This judgment is final but it may be subject to editorial revision.In the case of Kostenko v. Ukraine,The European Court of Human Rights (Fifth Section), sitting as a Committee composed of: Andreas Zünd, President, Diana Sârcu, Mykola Gnatovskyy, judges,and Viktoriya Maradudina, Acting Deputy Section Registrar,Having deliberated in private on 20 November 2025,Delivers the following judgment, which was adopted on that date:PROCEDURE1. The case originated in an application against Ukraine lodged with the Court under Article 34 of the Convention for the Protection of Human Rights and Fundamental Freedoms (“the Convention”) on 8 September 2021.2. The applicants were represented by Mr Y. L. Boychenko, a lawyer practising in Strasbourg.3. The Ukrainian Government (“the Government”) were given notice of the application.THE FACTS4. The applicants’ details and information relevant to the application are set out in the appended table.5. The applicants complained of the ineffective investigation into the disappearance of their father, who was later declared dead.THE LAWTHE LOCUS STANDI OF MRs Olena PETRIVNA KOSTENKO6. The Court notes that the present application was submitted by two brothers, one of whom, the first applicant, Oleksandr Fedorovych Kostenko, went missing in March 2022 after joining the Territorial Defence Forces of Kyiv. On 16 February 2024, his mother, Mrs Olena Petrivna Kostenko, has expressed her intention to pursue the application on his behalf. The Court notes that in various cases, where applicants have died in the course of the proceedings, it has taken into account the wishes of their heirs or close members of their families to pursue the proceedings before the Court (see, for example, X. v. France, Series A no. 234-C, p. 89, § 26, and Jama v. Slovenia, no. 48163/08, § 28, 19 July 2012). It sees no reason to reach a different conclusion in the present case where the disappearance occurred in life‑threatening circumstances over three years ago, and the first applicant had not been heard or seen since (see, among many judgments, Varnava and Others v. Turkey [GC], nos. 16064/90 and 8 others, § 143, ECHR 2009) and, therefore, accepts that the first applicant’s mother, Mrs Olena Petrivna Kostenko, can pursue the application initially brought by him. However, reference will still be made to the first applicant throughout the present judgment.ALLEGED VIOLATION OF ARTICLE 2 of the Convention7. The applicants complained of the ineffective investigation into the disappearance of their father, who was later declared dead. They relied on Article 2 § 1 of the Convention.8.

Outcome for Article 2: violation