"The state government has ordered an inquiry to investigate whether there is any foul play in his (Pul's) death," Chief Minister Pema Khandu told reporters here.
He said the police had been instructed to seize all available materials so that a genuine investigation process could be initiated.
The state government has declared a state mourning for three days.
Asked about the suicide note left behind by Pul as claimed by his supporters, Khandu said he had no knowledge of it but directed the police not to leave any stone unturned in the investigation process.