The dead man, who is due to be formally identified later, was discovered at a property in Tudor Road, Nuneaton at about 22:20 GMT on Friday.
A 28-year-old man from Nuneaton arrested on suspicion of assault was further arrested for manslaughter, police said.
He has been bailed until 24 April.
A man has been arrested on suspicion of manslaughter after a man in his 70s was found dead at a house.