The bond they share is way bigger and beyond the on-screen magic they have created with "Munnabhai" movies, but filmmaker Rajkumar Hirani says the upcoming biopic on Sanjay Dutt is not an attempt to publicise or promote his friend.
The 53-year-old director, who will be venturing into an uncharted territory with the biopic was initially hesitant to take up the project, but decided to give it a shot as he found Dutt's story very engaging.
Dutt, 56, has been serving a 42-month sentence at Pune's Yerwada jail after he was convicted for illegal possession of weapons in the 1993 Mumbai serial blasts case.
"I take so long to make a film. I will never make a film to propagate a friend. When they told me about the film I said I don't understand this world, till I actually heard his story.
"The first time he opened up and when I heard his story, I found it very engaging. That's the only reason I am going to make a film and I am only going to show him as he is," Hirani said in an interview on the sidelines of IFFI.
The filmmaker finds the "Agneepath" actor's life story very intriguing and feels it has all the possible elements which will contribute in the making of a great movie.
"It has many elements; it's a father-son relationship. There is humour, pathos. I get sucked in great stories. So, when I was writing something this came on my lap and I thought that's such a great story," he said.
The upcoming biopic will touch upon every aspect of Dutt's life- from the age of 17 till present.
Ranbir Kapoor has been roped in to play the lead role and Hirani says the reason they got the "Tamasha" actor on board was because he has seen the industry inside out and also knows Dutt on a personal level.
"We are showing Sanju's life from the time he was 17 to now, when he is 55. So obviously Sanju can't play it. We needed an actor who looks like a star, is a good actor, who can gain weight and become like that. Ranbir is a fantastic actor. He has grown a lot and he knows Sanju as well."
The director says Ranbir believed in the film and was eager to tell Dutt's story on celluloid.
"He understands that world. It is always good to have an actor who believes in the film thematically. Ranbir is somebody who has grown up in a film family and he understands the pathos in his (Dutt's) life.
