Mr Patrick Bakaleka, 60, is alleged to have beaten Ms Teddy Nakaweesa, 50, to death on Monday morning before being killed by angry residents, Mr Benard Mulabi, a detective at Bugiri Police Station, said.
Mr Micheal Owori, a nephew to Ms Nakaweesa, said at around 8am, he found Mr Bakaleka casually smoking at a shop located a few metres from the couple's house, saying he had come to buy a rope.
Mr Owori adds that he, however, managed to force his way into the house and found Mr Bakaleka fidgeting to hang himself with a rope, while the body of his auntie was slumped forward in a pool of blood.
Mr Owori reportedly raised an alarm that drew crowds to the scene and by the time police arrived at around 9am, Mr Bakaleka also lay dead in the compound.
Detective Mulabi, who corroborated most of Mr Owori's account, said: "Investigations are on to establish the motive, however, preliminary investigations suggest the couple was drunk at around 7am."