Former Assam MLA Hitesh Basumatary was arrested along with two other persons for allegedly being involved in efforts to form a terror group, police said on Saturday.
"Sophisticated weapons" along with ammunition were recovered from his house, Kokrajhar's Additional Superintendent of Police Nabaneeta Sharma said.
Basumatary was arrested on Friday night from his residence in Baksa district, she said.
The two other persons arrested were Bodoland Jatiya Suraksha Manch working president Daorao Dekhrab Narzary and Bodoland Contractor Association president Bikram Daimary, she said.
While Narzary was arrested from Kokrajhar, Daimary was arrested from Udalguri.
"We had received information that some people were trying to form a new terrorist outfit and in this connection, we have arrested these persons," Sharma said.
When produced at the court of the Chief Judicial Magistrate in Kokrajhar, Basumatary and Daimary were sent to five days in police custody. Narzary was sent to 14 days in judicial custody, she said.
"Further details will be known after the investigation," the officer said.
Basumatary was elected MLA from Chapaguri in 2011 on a Bodoland People's Front (BPF) ticket.