Assam chief minister Himanta Biswa Sarma on Thursday requested Mamata Banerjee for a “thorough investigation” into the circumstances surrounding the death of an IIT Kharagpur student from Tinsukia district.

Faizan Ahmed, a 23-year-old third-year student of mechanical engineering, was found dead in his hostel room on October 14.

His parents filed a complaint with Kharagpur police and requested the police superintendent of West Midnapore and the inspector-in-charge of Kharagpur (Town) police station to start an investigation because they suspected foul play.

They now demand a CBI inquiry.

The Assam chief minister’s office said on Thursday evening that Sarma had sent a “request letter” to the Bengal chief minister seeking her intervention for a thorough investigation to “unearth” the truth leading to the death of the “bright student”.

Sarma said Faizan’s death had “caused a deep sense of grief across the state”. Sarma had tweeted last week:

“Deeply pained by the unfortunate death of Faizan Ahmed, a bright young student from Tinsukia studying at the prestigious IIT Kharagpur. My condolences to his family and friends. May his soul rest in peace.”

Faizan’s aunt Salma Ahmed told The Telegraph they want a thorough probe into the death. “It is not a case of suicide.… It is murder. You should have seen the body. It had injury marks and was decomposed. We did not get any help from the authorities and the police when we rushed to Kharagpur on Saturday.... We want justice, we want a CBI probe...”

Salma, who lives in Guwahati, said on Thursday evening.

She said Kharagpur Sadar BJP MLA Hiranmoy Chatterjee came to meet the family in the evening.