Abdul Ahad Dar, working as informer in IRP 3rd battalion, consumed the substance in Beerwah area of the district, 25 kms from here, they said.
Dar was shifted to a hospital here, where the doctors declared him brought dead.
A case has been registered in this regard, police said.
In a separate case, a 19-year-old boy allegedly committed suicide by hanging himself from the ceiling at his residence in Anantnag district.
The deceased has been identified as Basit Ahmed Khan.