Tanveer Ahmed, who had crossed over to Pakistan for arms training in 2002, was arrested in Nalwa area, they said.
A chinese pistol with 30 rounds, a wireless set, a satellite phone and two hand grenades were recovered from his possession.
During interrogation, Ahmed revealed he had crossed over to Pakistan in 2002 via Poonch sector after joining the Hizbul Mujahideen outfit, police said.
He was imparted arms training in Pakistan and PoK, he told his interrogators.
The militant had returned to Doda with an aim to revivie terror activities in the region, police said.