Previously, following his match against Welsh opponent Nathan Howells at Ulster Hall, the 28-year-old was rushed to intensive care. The bout, which was Cooney s first defense of the Celtic super-featherweight title, was halted in the ninth round.

Cooney was later diagnosed with an intracranial hemorrhage. His promoters, MHD Promotions, released a statement expressing their deep sorrow.

"After a week of fighting for his life, John Cooney has unfortunately passed away," they stated, expressing gratitude to the medical team at Belfast’s Royal Victoria Hospital for their care and support.

Cooney had claimed the Celtic super-featherweight title in November 2023 by defeating Liam Gaynor, but spent much of the subsequent year recovering from a hand injury. He made his return to the ring with a non-title win before facing Howells.

The boxing world has been paying tribute, with fellow fighter Conrad Cummings referring to him as a “warrior,” while Gaynor, who retired after his fight with Cooney, offered his heartfelt condolences.