The 71-year-old was arrested on Saturday, four days after a man was found with lacerations to his head at a house in the town.
Malcolm Cox, 84, from Bell Road, was discovered just before 08:30 GMT on Tuesday.
He was taken to the North Hampshire Hospital in Basingstoke and died the following day.
A 38-year-old woman from Andover was also arrested on suspicion of murder and released on bail.
A man arrested on suspicion of murder in Andover has been bailed until March 7.