Mahendra (40), who was arrested last night from the Sarai Kale Khan area, has told police that the incident took place last year.
"Mahendra told us that he, along with his accomplice Riyaz had kidnapped Pradeep, from outside his house in the Amar Colony area of south Delhi in July 2012. They then made a ransom call of Rs 4 lakh to his father," said a police official.
Although Riyaz was arrested in August for the kidnapping, he never disclosed to police about the gruesome killing of the boy.
After the incident, Mahendra spent some time in Ludhiana, and then lived in Srinivaspuri under a fake identity.
On his instance, police recovered the mortal remains of the boy from the jungle which would be sent to a forensic laboratory for verification, police said.