Karachi police are investigating the alleged kidnapping, sexual assault, torture and murder of a four-year-old boy, who passed away at the Jinnah Post-Graduate Medical Centre (JPMC) on Wednesday.

According to a first information report registered at the Sir Syed Police Station on the complaint of the victim's father, the child had left his house in Bilal Colony on Tuesday morning to play with his friends. A couple of hours later, he was found in a semi-conscious state with torture marks on his body. The complainant further said that there was blood in the victim's stool.

The victim's father told police that he suspected that someone had kidnapped his son and attempted to subject him to sodomy.

The victim was first taken to the Abbasi Shaheed Hospital and was later shifted to the JPMC, where he passed away earlier today, said Dr Summaiya Syed, the hospital's additional police surgeon.

She said that an autopsy had not been conducted and the hospital had only issued a death certificate, which mentioned assault as the cause of death. She added that sexual assault of the child could not be ruled out.

Station House Officer (SHO) Nawaz Ali Brohi, meanwhile, said that an autopsy was not required as the victim had been examined by the doctors when he was brought to the hospital.

The SHO said that the perpetrator may have been a teenager.

Police had earlier filed an FIR under Sections 363 (punishment for kidnapping) and 337(A) (Shajja /bodily injuries) of the Pakistan Penal Code. The police will now include a murder section as well.