NEW DELHI: A 24-year-old labourer allegedly killed his wife and their one-and-a-half year old son following a fight in Delhi, police said on Saturday. The accused has been arrested, they said. Brajesh suspected that his wife was having an extra-marital affair and killed her and the child after a fight over the issue, police said. The incident took place late on Friday night at northwest Delhi’s Subhash Place, police said. According to the police, Brajesh suspected that his wife, with whom he got married in 2016, was having an extra marital affair. The couple often fought over their issue. Brajesh even suspected that their son was not his child but of the man with whom his wife was allegedly having an affair, police said. The accused used sharp-edged weapon — kitchen knife and screw driver — to kill the duo, the police added. Deputy Commissioner of Police (Northwest) Jitendra Kumar Meena said information about the incident was received on the intervening night of Thursday and Friday. Immediately, police reached the spot and the injured were taken to a hospital where they were declared brought dead, he said. “A case under section 302 (murder) of the Indian Penal Code has been registered and accused has been arrested. Further investigation is in progress,” the DCP said.