Police said the former director general of police shot himself with a revolver at his residence in Barowari locality.
He was a suspect in the multi-crore chit fund scam and the CBI, in the course of its investigation, had raided his house last month.
Police officials said Barua had been hospitalised after his residence was subjected to search recently in connection with the multi-million rupee Saradha scam.
Barua came under a cloud after former Saradha manager Dibon Deka named him as recepient of slush funds from Saradha chief Sudipta Sen.
The former police chief denied the allegations stoutly and claimed he had been framed but colleagues say he was distraught after questioning by sleuths of the Central Bureau of Investigation (CBI).
Many former police officers have been hauled up by the CBI in West Bengal for close links with Saradha . One former West Bengal police chief Rajat Majumder is in jail now.
While CBI alleges he is not cooperating with the investigations and concealing his role in the scam, Majumder says CBI is pressurizing him to 'substantiate their version' to nail top Trinamul Congress leaders including Chief Minister Mamata Banerji.
Another senior police official in Bengal Deben Biswas has also been questioned.