The deaths began last week after a man in Punjab province bought the treats to celebrate the birth of his son.
He and 11 other relatives are among the dead - in all 77 people were affected. Five remain in a serious condition.
Police have arrested two owners of a local sweetshop and one of their employees while the source of the contamination is investigated.
Officials suspect pesticide from a store next to the shop may accidentally have found its way into the laddoos - ball-shaped sweets popular at special occasions.
Laboratory tests are being carried out after police reportedly found sachets of pesticide inside the sweet shop.