Calcutta, June 3 :     A triangular love affair could have led to the ghastly killing of a 27-year-old computer professional, Kunal Bose, in the Bypass area on the city's eastern fringe. Bose's mutilated body was recovered near the Dhapa dumping ground, on the Eastern Metropolitan Bypass, on May 26 . After almost a week, the police on Saturday arrested Nantu Roy, 26, from Behala and propounded the theory of a love triangle as a possible motive for the murder. Roy, a promoter, was picked up from his Adarshnagar residence in Behala. 'We are probing Nantu's role in the crime and examining whether some others are involved in the killing,' said the officer-in charge of Tiljala police station, Jugal Kishore Mukherjee. Mukherjee said the killers chopped up the victim's body before tossing it in front of a speeding lorry on the Bypass to make it look as if he was killed in an accident. On May 26, motorists passing along the Bypass informed the police that a man was lying in a pool of blood near the Dhapa dumping ground. The police set off for the spot and took the victim to nearby Chittaranjan Hospital. 'Kunal was alive when he was being treated in hospital. But he was not able to speak, nor was he carrying an identity card,' said Mukherjee. The OC, who is heading the investigation, said Kunal, before succumbing to his injuries, gave a statement in which he mentioned what had happened to him. 'Although he could barely speak, we were able to glean the names of some assailants from the dying declaration,' said the OC, adding: 'We have started the investigation picking up leads from what he had said minutes before his death.' Preliminary investigations reveal that Kunal had left his Aswini Dutta Road home with Nantu at 6.30 pm on May 26. The two walked to Gariahat, where they got into Nantu's car and sped off for the Bypass. Kunal did not return home that night and his worried mother, Anuradha, registered a missing diary at Lake police station. Officials said Kunal's wife, Munmun, 24, is a salesgirl at a cellphone shop in Kidderpore. Married for eight years, Kunal and Munmun have two sons. Police said Kunal was short- tempered and often ill-treated his wife. Neighbours corroborated the allegation, saying Kunal even assaulted Munmun on occasion after a quarrel. Munmun found a friend in Nantu, and they were often spotted together. Munmun introduced Nantu to Kunal. In course of time, Kunal and Nantu became friends. Nantu became a frequent visitor to the couple's house. Officials said Kunal cottoned on to the affair and started questioning his wife. 'This must have led to strained relations ,' they added.