Several police officers including state ATS chief Rakesh Maria and Thane's police commissioner Kris Pal Raghuvanshi, who once headed the ATS, were present at the funeral.
Meanwhile, it was still not known as to what caused the officer to end his life. The Thane police maintained that they were investigating the case.
According to police, Banerjee (45), along with his family members, had gone for lunch at a local restaurant yesterday and while conversing with them, he suddenly pulled out his revolver and shot himself.