The Saturday Night Takeaway star took to Twitter to thank his fans for their "messages of sympathy" as he confirmed the tragic news of his "darling" brother's passing. Dermott, a beloved Roman Catholic priest, reportedly collapsed earlier this week following an unknown illness and was hospitalised in North Durham.
WATCH: Declan Donnelly and Ant McPartlin attend charity event
Posting on Twitter to the account he shares with his presenting partner and best friend, Ant McPartlin, Dec penned: "I am heartbroken to tell you that my darling brother Fr Dermott, @TweeterPriest, sadly passed away this afternoon."
He added: "We are all beyond devastated. Thank you for your messages of sympathy and support, they are appreciated."
A spokesman for Dec added: "It is with great sadness that we confirm the death of Fr Dermott Donnelly who died peacefully this afternoon in hospital surrounded by his family and close friends. We ask for the utmost privacy for the Donnelly family at this difficult time."
Father Dermott was just 55 when he died
On Friday, Dermott's parish confirmed his death in a statement issued by the Bishop of Hexham and Newcastle. It read: "It is with great sadness that I inform you of the death of Fr Dermott Donnelly who died peacefully this afternoon in hospital.
"This has come as a great shock to all of us. Please pray for the repose of his soul and keep his family, especially his mother, in your prayers at this difficult time. Funeral arrangements will follow when finalised."
Dec's older brother officiated his wedding to Ali Astall
Dec had a very close relationship with Dermott, who officiated his wedding to wife Ali Astall in 2015.
He previously revealed he had considered following in his older brother's footsteps, saying: "My brother Dermott trained to be a priest. When I was about 14, I did briefly consider following in his footsteps.
"Then, one day, I got the bus home from school, and it was full of lasses from the local girls' school, Sacred Heart. I knew right there and then that the priesthood wasn't for me."
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