Kasim Jameel, who led the aid convoy to Syria on which Alan Henning was kidnapped, has said he is "distraught" at the news of the death Mr Henning.
Mr Jameel spent almost two months searching for his close friend after the 47-year-old taxi driver was captured in Syria.
"I'm absolutely heartbroken. I lost someone that was closer than my own brother to me," he said in an emotional interview.
A video showing the killing of Mr Henning, who was from Eccles in Salford, was released by Islamic State (IS) on Friday.
Mr Jameel spoke to the BBC's Catrin Nye.