The case which started out as that of suspected “kidnapping” of an infant in Delhi's Mukundpur took a tragic turn on Sunday, with the police suspecting murder of the 10-month-old.The accused has been detained and is currently being interrogated by the police. (HT Photo/ Representational)The cops allegedly became suspicious after questioning the infant's father, and thereafter learnt of his role in the killing of the child, PTI news agency cited police sources as saying.The accused has been detained and is currently being interrogated by the police, with the cops suspecting the involvement of more family members in the case, according to sources.Also Read | Palwal man kills wife, daughter; flees with infant son: PoliceAccused drugged wife, dumped daughter's body in tankThe accused came under the police lens after his version of events raised suspicion, and allegedly confessed to having killed his 10-month-old daughter. According to police sources cited by PTI, the accused mixed some intoxicating substance in his wife and elder daughter's food or drink and gave it to them before killing the infant on the intervening night of Saturday-Sunday.After killing the 10-month-old, the man dumped the child's body in a septic tank, police sources said, adding that a search is underway to recover the infant's body.Family claimed infant was missing from homeThe case was initially suspected to be that of kidnapping as the infant's family claimed that child had gone missing when her father had stepped out to buy milk on Sunday morning.The 10-month-old's grandfather told reporters that when his son returned home, he could not find the infant, following which police were called in and a search operation was launched, PTI reported. “We called people from the neighbourhood and started searching for her, but we could not find her. We informed the police, and the hunt is on,” the granfather said, according to PTI.Also Read | 20-year-old held for abandoning infant daughter in Rohini drain Meanwhile, the child's mother Surya said that when her husband returned home, he had found their elder daughter and her in an unconscious state. “He woke me up by calling out my name and shaking me. When I regained consciousness, I found that even my elder daughter was unconscious. We woke her up too, and then realised that our youngest daughter was missing, but we had no idea where she was,” the mother said, adding that she does not step outside and did not know who had taken her child.The incident triggered panic in the locality in Mukundpur in Delhi, an official said, with the police saying efforts were underway to trace the child. Crime and local police teams were deployed.