The body of Nayan Jain was found in a drain at Mhasa village this morning following which the arrests were made, they said.
The boy was allegedly abducted yesterday and taken to Wangni village on a bike by Raju More (24), Devraj Kushwaha (22) and Vijay Dubey (19) after they told him that his father wanted to see him, said Additional Superintendent of Police (Thane Rural) Avinash Ambure.
"He was sedated and kept in a bungalow at Wangni. The accused called his father and demanded Rs 15 lakh for Nayan's release, to which he agreed," Kadbule said.
"After collecting the money yesterday, More went to Kalyan to meet Dubey who told him to kill Nayan as the latter knew them," he said.
"More and Kushwaha bound and gagged the boy, took him to Mhasa and drowned him in the nullah," Kadbule said.
