Former West Bengal Chief Secretary Alapan Bandyopadhyay has allegedly received a death threat through a letter addressed to his wife.
A letter addressed to Mr Bandyopadhyay's wife Sonali Chakraborty, Vice-Chancellor of Calcutta University, said: "Your husband will be killed, nobody can save the life of your husband."
Kolkata Police have filed an FIR after Ms Chakraborty filed a complaint about the alleged threat at Hare Street Police Station.
"Over the complaint of Sonali Chakraborty Bandopadhyay, Hare Street PS lodged FIR, dated October 26, under section 170/419/500/506 of Indian Penal Code against unknown people," said the police in an official statement.
Mr Bandyopadhyay is currently serving as the chief adviser to West Bengal Chief Minister Mamata Banerjee.
Further investigation is underway.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)