Keonjhar: Police here registered a zero FIR on Saturday after the family of a 15-year-old boy complained that he was sodomised by four men in Tamil Nadu. Sources said the survivor was allegedly employed illegally as a labourer at a textile unit in Tamil Nadu.A police officer said: “After receiving a complaint, a zero FIR has been registered and then transferred to Tamil Nadu police where the incident happened for registration, investigation and action.”Sources said the 15-year-old boy is battling for his life at a hospital in Cuttack after the alleged crime.According to the complaint, the incident took place on Nov 4, when four youths allegedly subjected him to unnatural sexual assault, following which his health deteriorated severely.The boy was reportedly found lying in a critical condition in his room by a relative, who facilitated his return to Odisha on Nov 8. The family lodged a complaint with Keonjhar police on Friday, demanding immediate arrest of the accused.