Calcutta, July 31 :    Calcutta, July 31:  Unknown assailants murdered 34-year-old businessman Achintya Karmakar, a descendant of Uma Charan Karmakar, the man who popularised the dari-palla (weighing scales), at his Narkeldanga Main Road residence on Tuesday. The victim was found in bed with multiple stab wounds on the back. Karmakar was a bachelor and police suspect business rivalry could be a motive behind the murder. They are interrogating Karmakar's friends, who visited him regularly. Sniffer dogs have also been pressed into service. Karmakar lived on the ground floor of a two-storeyed building, the first floor of which is occupied by his parents and his elder brother. Karmakar had friends dropping in on him regularly, and some would stay back for the night. Septuagenarian Sib Sankar Karmakar, the victim's father, said: 'The business was looked after by Achintya and my elder son Jayanta. Achintya would travel to different states on business. He had a number of friends visiting him frequently. But I cannot say who had come on Monday night. Besides, none came back after the incident.' Jayanta, Achintya's brother, said: 'Today, around 6.20 am, when I came to see my son off, I discovered something red trickling out of his room. I thought it was some kind of paint and since I was in a hurry, I decided to check it out after seeing off my son. 'On returning, I found that the wooden door to Achintya's room was half-open. I found him in bed with several stab wounds on his back, from which blood had oozed out. I raised an alarm and my wife and parents rushed down. Beleghata police were informed. They came and took charge of the body.' A relative of the Karmakars felt there were rifts and heartburn in the clan over the family business. 'Not everyone was happy with the way Achintya's grandfather had divided the business. Of late, Achintya himself was doing quite well for himself, which the others resented,' maintains the relative, convinced that the family is keen to divert attention from the internal business rivalry. Neighbours, though, were not quite approving of Achintya's recent ways. 'Of late, he was thick with some shady characters who stayed with him for nights together,' complained a neighbour. S. Bhattacharya, investigating officer from Beleghata police station, said: 'We are interrogating family members and trying to locate Achintya's close friends.'