A senior Assam Police official said that the decision to question Vanlalvena was taken following his "controversial interview to the electronic media in which he allegedly has warned the Assam police with objectionable words".
Contacted by IANS for a response, Vanlalvena said: "I do not have any comment now. I have not received any official information."
The most violent clashes along the Assam-Mizoram border left six Assam Police personnel dead and around 100 civilians and security personnel of the two neighbouring states injured, including an Inspector General of Police in Assam and Cachar Superintendent of Police Vaibhav Chandrakant Nimbalkar.
Assam Police's Special Director General G.P. Singh, in a tweet, said: "Assam police team including officers of CID are leaving for Delhi to take lawful action relating to conspiracy behind the incident in light of media interviews of Rajya Sabha MP Sri K Vanlalvena indicative of his active role in conspiracy."
In another tweet, he said that a case has been registered at the Dholai police station in Cachar district in the killing of Assam Police personnel, under various provisions of Indian Penal Code, and the Arms Act besides Prevention of Damage to Public Property Act.
An Assam Police spokesman said that a "picture gallery" of Mizoram Police personnel and civilian miscreants who fired at Assam Police has been prepared, and is being further updated.
"They would be brought to law," he said, adding that the state also announced a reward of Rs 5 lakh for information leading to the arrest of the individuals involved in the "barbaric killing of the Assam Police" personnel.
Meanwhile, the Assam government has transferred Hailakandi Superintendent of Police Ramandeep Kaur to Cachar as incumbent Nimbalkar, who had sustained serious injuries in the Monday's firing and clashes, has been airlifted to Mumbai. IPS officer Gaurav Upadhyay has been posted as new SP of Hailakandi.
An uneasy calm now prevails on the border areas where the Central Reserve Police Force and Assam and Mizoram Police have been posted.
The Chief Secretaries and DGPs of Assam and Mizoram met Union Home Secretary Ajay Bhalla on Wednesday in Delhi to discuss the prevailing situation, and it was decided to deploy "neutral" Central Armed Police Force, headed by a senior CAPF officer, along National Highway 306 to keep peace along the border".
The Mizoram Chief Secretary also complained of the problems faced by the state due to the "economic blockade" by Assam and the destruction of railway tracks leading to the state's lone rail head at Bairabi.