NEW DELHI, July 19 -- A 36-year-old man was allegedly murdered by his wife and his cousin -- who were in an illicit relationship -- in West Delhi's Uttam Nagar on Sunday. The duo tried to pass off the murder as an accidental electrocution, but the truth began to unravel after the victim's brother stumbled upon incriminating messages, investigators aware of the case said on Friday. Police identified the deceased as Karan Dev, a resident of Om Vihar. Police identified his wife, Sushmita Dev, 35, and his 24-year-old cousin, Rahul Dev, as the accused. The case came to light on Sunday morning when police received a call from Mata Rooprani Maggo Hospital in Uttam Nagar, reporting that a man had been brought in dead, according to deputy commissioner of police (Dwarka) Ankit Singh. "The patient, Karan, was declared brought dead and was shifted to Deen Dayal Upadhyay hospital for post-mortem," he said adding that on Sunday, no allegations were raised by family members who also expressed their wish to waive off the post-mortem examination. "The family told us that Karan died of electrocution after he came in contact with the wire from the extension cord which has a high level of electricity running," an officer aware of the matter said, asking not to be identified. However, given the age of the deceased and the unclear circumstances, the police proceeded with a postmortem the next day. "The doctor confirmed that he had died of electrocution but also verbally told us that the victim's stomach contained some sleeping pills, which raised suspicion. The viscera was collected and preserved for further analysis," the officer cited above said. The investigation took a decisive turn on Wednesday, when Karan's younger brother, Kunal Dev, approached police with screenshots of WhatsApp messages exchanged between Sushmita and Rahul. The chats appeared to lay out a step-by-step plan to murder Karan. "Hence, a preliminary enquiry was conducted and on the basis of enquiry and the material available during inquest proceedings, a case on charges of murder was registered," DCP Singh said adding that investigation has been taken up. "Sushmita was updating Rahul in real time on the night of July 12-on what she was feeding Karan, whether he had fallen asleep, and at what point she was struggling to execute the plan. At one point, she called Rahul over to help her," said an officer familiar with the probe. Based on the chats, police said their investigation led them to believe that Sushmita spiked Karan's food with sleeping pills. "It appears that the wife first gave him the pills in his food. She then cut the heavy wire attached to the extension cord from a point and when he was in deep sleep, she and Rahul touched his finger to the live wire after switching it on," the officer said. "Touching a high-voltage extension cord like that could lead to fatal electrocution," the officer said. Once they were sure Karan was dead, Sushmita pretended he wasn't waking up and told the family that he had died from touching a live wire. Police said that Sushmita and Karan had been married for several years and had a six-year-old son. The couple had fallen in love before marriage. However, about a year ago, Sushmita began an affair with Rahul, who lived in the same building. "Sushmita didn't want a divorce, partly because of their son and partly because of social stigma. So, they decided to eliminate Karan and stage it as an accident," the officer said. On the basis of Kunal's complaint and the chats, police registered a case of murder. Both Sushmita and Rahul have been detained and are being interrogated....