Oleksandr Kostornyi, aged 75, who had been convicted of treason in connection with the case involving the transfer of information to Russia regarding the Yavoriv firing range in the Lviv region, has died in prison. According to media reports, he died in June 2026, and his death was publicly announced on 5 October following a post by his daughter. The State Penitentiary Service confirmed this information to regional media outlets.
Briefly about the main points
- Kostorny died in prison in June 2026.
- The information was made public following a post by his daughter on 5 October.
- The State Penitentiary Service confirmed the prisoner’s death to regional media.
- In 2024, the court sentenced him to 15 years’ imprisonment.
- The cause and exact circumstances of the death have not been made public.
The death was confirmed following a report from the family
«Pershyi Zakhidnyi» was the first to report the death, citing a post by his daughter Kostorny on social media. The publication subsequently received confirmation from the State Penitentiary Service.
According to local media reports, the convicted man was serving his sentence at Correctional Colony No. 122 in the Dnipropetrovsk region. The cause of death and the exact circumstances surrounding it have not been officially disclosed.
The appeal court upheld the sentence for treason
On 23 May 2024, the Halytskyi District Court of Lviv found Kostornoy guilty under Part 1 of Article 111 of the Criminal Code — high treason. He was sentenced to 15 years’ imprisonment with confiscation of his property.
During the trial, Kostorny did not admit guilt. He claimed that he had sent an acquaintance a map of the area, on which he had allegedly marked spots for mushroom picking and fishing. The court did not accept this version of events.
In March 2025, the Ternopil Court of Appeal dismissed the appeals lodged by the convicted person and his defence counsel, upholding the sentence.
The investigation linked the case to the handover of a map of the FSB training ground
According to the findings of the investigation and the court, following the start of the full-scale invasion, Kostorny collaborated with representatives of the Russian special services and gathered information on military installations, weaponry and critical infrastructure in the Lviv region.
On 4 March 2022, he sent a map of Yavoriv to an FSB officer via Telegram military training ground. It showed the military towns of the International Centre for Peacekeeping and Security, as well as the locations of the barracks and halls of residence.
Nine days later, Russian forces launched a massive missile strike on the city centre. According to the Office of the Prosecutor General, more than 60 people were killed and over 160 were injured as a result of the attack. In the case files, the transfer of the map was regarded as information that could have been used by the Russian side to carry out the strikes.
