A man found unconscious and with serious facial injuries in the front garden of a house in Warwickshire has died.
Ranjit Singh, aged 44, was discovered outside the house in Mawnan Close, Exhall, at 0830 BST on Tuesday.
He was taken to hospital but died on Wednesday.
Three men, aged 51, 55 and 61, arrested on Tuesday on suspicion of causing grievous bodily harm are now being questioned on suspicion of murder.
Police said they were trying to find out where Mr Singh, who was known as Bitu, had been and who he had been with over the past few days.
Det Insp Kate Tomkinson said: "Bitu was a familiar face around Coventry and Exhall.
"We urge anyone who knew Bitu, or who recognises him, and who saw him in recent days, to come forward."
She added the attack, which she described as "extremely violent", had not been random.