The Ludhiana police on Saturday arrested a father-son duo for allegedly killing former Manewal sarpanch Navtej Singh over a land dispute.The police said the conspiracy was hatched by a person with whom the deceased had a long-standing property dispute. However, the killing was carried out by Roor Singh, a driver employed with a bread company, and his son, Jaswinder.They said Navtej had gone to inspect the ongoing work on his 30-35 acre land in Manewal village on the evening of October 3. While returning to his home in Ghumar Mandi, Navtej was attacked by two motorcycle-borne assailants near Ladhowal. The investigators said the murder stemmed from a dispute over 1.5 kanal land linked to the deceased’s sister.