Officials of the observation home tried to push the matter under the carpet, but the victim raised his voice and filed a complaint with the Simlapuri police.
The police have registered a case against Harpreet Singh alias Shaktiman, Vishal Kumar and Deepak.
The victim, Tarlok Singh alias Tukka of Muktsar, was lodged in the observation home on November 27 for burglary.
According to the victim, the accused abused and thrashed him. At 10 pm on the day when he was brought to the centre, the accused dragged him in a room and sodomised him.
"I screamed for help, but no one came to rescue me. After sodomising the accused threatened me not to tell anyone about the matter," Tarlok said.
ASI Mohammad Rashid of Simlapuri police station said the police would take the accused on production warrant from observation home for investigation.