Which one among the following is not a branch of the Central Industrial Security Force?

The Central Industrial Security Force (CISF) is organized into three primary branches as per the CISF Rules: Executive Branch, Ministerial Branch, and Fire Service Branch. The Executive Branch is responsible for the protection and security of industrial undertakings and government infrastructure. The Ministerial Branch handles administrative and clerical tasks. The Fire Service Branch is a unique wing of the CISF, making it the only Central Armed Police Force (CAPF) in India with a dedicated fire-fighting unit. There is no separate Investigative branch within the formal organizational structure of the CISF. Investigation of crimes is primarily the domain of the local police or specialized agencies like the CBI.