Dharmendra was yesterday found hanging from a tree, police said.
His father, Om Prakash, told police that some of his relatives were threatening Dharmendra for unknown reasons.
Prakash named Bodh Raj, Sunny and Aman in a complaint. A case under relevant sections of the IPC was registered against the accused, police said.
Meanwhile, some residents today blocked the Pathankot- Jalandhar national highway, demanding that the accused be arrested immediately.