Njambi, 24, died in January after she was physically assaulted and forced to swallow acid that her attackers later doused her with.
Ex-Riruta MCA Ndung’u and two others have been charged with her murder.
Former Riruta Ward Rep, who has been charged with killing his estranged wife had accused her of infidelity, a witness told the court.
Mr Samwel Ndung’u had also threatened to kill a man he suspected was having an illicit affair with Lucy Njambi, Lydia Nduta, a witness, told the court on Monday.
