The boy was picked up by the officers of Chitpore police station on July 3 for questioning in a burglary case.
Later, the family members of the boy, who works as a helper in a shop, alleged that the boy was sexually and physically tortured by the police in the lock-up. It was alleged that a stick was shoved in the boy's anus.
"A complaint was lodged to Deputy Commissioner of Police (North) about the torture in lock-up. He is looking into the matter but no signs of physical torture were found during medical examination," Joint Commissioner of Police (Crime) Pallab Kanti Ghosh told PTI.