New Delhi, Jan. 5 -- A 75-year-old man and his 65-year-old wife were found dead at their house in Shahdara early on Sunday, police said, adding they were investigating the incident as a possible murder and robbery. The bodies of Virender Kumar Bansal, a retired school teacher, and his wife Parvesh Bansal, a homemaker, were in separate rooms in the house, in Rama Nagar Extension, where they lived on the third floor. Initial investigation suggested Virendra was struck on the head and face with a heavy object and Parvesh was strangled to death. Parvesh's body was also missing jewellery, police added. Officers said they were informed about the crime by the couple's son, Vaibhav Bansal, 28, who was taken into custody and was released after interrogation. Vaibhav lived with the couple and works as a gym trainer in Ghonda. He found their bodies at 12.15am when he returned from the gym and called the police. A senior police officer said they received the call at 12.30am. " Vaibhav told us that his parents were found dead. He said they had been killed by an unknown person," said the officer, who asked not to be named. The television was on and the volume was loud when Vaibhav entered the house, which may have drowned the victims' screams, police said, quoting him. Shahdara deputy commissioner of police Prashant Kumar Gautam said, "The investigating officer along with police staff reached the spot where Vaibhav met the police team and said that someone had killed his mother and father. Two bodies were found in separate rooms in the house". The couple also have a daughter, Ekta, who lives with her husband in Meerut. Officers are investigating a potential robbery because of Parvesh's missing jewellery. However, investigators pointed out that the house was not broken into. The deceased are originally from Baghpat in Uttar Pradesh. CCTV cameras installed at the house's gate and in the street were not working. Police are also questioning neighbours and other family members and working to obtain Vaibhav and the couple's call data records....