The National Investigation Bureau (NIA) on Friday started interrogating Professor of Indian Institute of Technology, Guwahati (IIT-G) Arupjyoti Saikia at Sonapur branch.
The NIA also interrogated the Adviser of Krishak Mukti Sangram Samiti, Hussain Mohammad Shahjahan.
Saikia was also interrogated on February 3 for five hours.
As per reports, 42 scholars and academicians, including noted historian Ramachandra Guha, wrote to the NIA on Monday last in support of IIT-Guwahati professor Arupjyoti Saikia.
NIA had summoned him as the witness of the case which the Krishak Mukti Sangram Samiti (KMSS) leader Akhil Gogoi has been arrested on February 1.
It may be mentioned that Assam minister Himanta Biswa Sarma had indicated to a leading academician from the state, who tried to orchestrate the burning of the Assam Secretariat in Dispur.
Sarma had earlier hinted at having electronic evidence of a prominent intellectual from a Central Government institution who had been coordinating with the attackers without giving out a name.