Exploring in his films the dark underbelly of the underworld is what Ram Gopal Varma is known for. After making underworld dramas, the filmmaker puts the spotlight on the dark secrets of the police department through his film "Department", releasing Friday.

"Department" focuses on a group of encounter specialists working with the Mumbai Police force and their different perspective towards the underworld.

Concerned about the underworld's increasing terror and other criminal activities, the top cops along with the home secretary and the home minister hold a secret meeting and decide to form a special unit called - The Department.

The team includes inspector Mahadev Bhosle (Sanjay Dutt), leader of the encounter squad, and Shivnarayan (Rana Daggubati), an encounter specialist. Both the cops have different ways of dealing with the gangsters.

While Shivnarayan follows principles and ethics, Bhosle is completely opposite. The film shows conflicts of interest and struggle for power among the cops.

Apart from Sanjay and Rana, the film also features megastar Amitabh Bachchan as gangster-turned-politician Sarjerao Gaikwad. Anjana Sukhani, Vijay Raaz, Abhimayu Singh and Lakshmi Manchu form the rest of the cast.

The film has been extensively shot with the 5D and 7D cameras, and the filmmaker fondly calls it "rogue filmmaking".

"Department is a hard hitting action drama and I wanted to apply a completely new language of cinema in terms of both its camera work and editing," said Varma.

The technology and methodology I adopted in the course of filming 'Department' is what I would call 'rogue filmmaking'. Department has not been shot with canon 5D alone... it's just one of the 7 types of cameras used.

"It's been shot in multiple formats with 5D, 7D Lumix Gopro Sony Nx5 and 60D... each camera was used for its own uniqueness in capturing a shot," he added. Even Sanjay admits he was amazed to see the minute details that the camera has captured.

Varma's films are incomplete without a raunchy number and this time he has roped in Brazilian model of Indian descent Nathalia Kaur to perform on the song "Dan dan Cheeni", which, he says, is a tribute to Tamil superstar Rajinikanth. The song was earlier offered to Sunny Leone, but she couldn't do it.

A new version of Amitabh's iconic song "Thodi si jo pee li hai" from 1982 release "Namak Halal" has been used. In this number, Sanjay shakes a leg with the megastar.

Also Varma's films are incomplete without controversy. Here too screen-play writer Danish Raza filed a police complaint against the director for allegedly not paying him his dues for the film.