Last seen in the issue-based film "Lamhaa", Sanjay Dutt returns to entertain his audiences with the comedy "Knock Out". While he will play a grey character, Irrfan Khan will help him spice up the drama that releases Friday.

Directed by Mani Shankar and produced by Sohail Maklai, the film is said to be made at a budget of about Rs.300 million.

It was reported that Shankar has taken inspiration from Hollywood venture "Phone Booth" for "Knock Out", which also features Kangana Ranaut, Sushant Singh and Gulshan Grover. But the director denied it, saying his project is based on a strong plot in which Sanjay's character will cheat those who have looted India and have many secret bank accounts across the world.

"There's no similarity between 'Phone Booth' and 'Knock Out'. The only similarity is that the guy (Irrfan) is trapped in a phone booth, but the similarity starts and ends there. 'Knock Out' tells an entirely new story, " Shankar said.

In the film, Sanjay plays a lone ranger who owns latest weapons and gadgets and is a man who trusts and depends on no one. Working alone, he effortlessly uses his wit, his skills at hand-to-hand combat, and his love for technology to manipulate and trap his elusive target - an investment banker played by Irrfan.

In the movie, Irrfan's character make his way to the upper echelons of power and unwittingly holds the key to India's destiny. He is a man consumed by his own obsessions, an extremely clever and unstoppable foe.

But Sanjay strips Irrfan of his arrogance and attitude and locks him in a tangle that could be unravelled by only one way - leading to the biggest counter-heist.

As the drama reaches its action-packed climax in the film, the live action unfolds before television cameras, courtesy Kangana Ranaut, who plays a TV reporter.

About the role, Sanjay said: "When Mani narrated the script, I was raring to go. After the first day of the shoot, I realised I was doing the most difficult thing - I had to imagine Irrfan Khan was in front of me, and deliver dialogues without seeing him and his reactions. Acting means participating, and it was tough to visualise and perform."

Both the actors have donned new look for the film. While Sanjay is seen sporting small beard, Irrfan has grown his hair for the film. Irrfan also admits that it was difficult for him to act because he also had to imagine Sanjay.

"It was a bit tedious. There was no face to look at. All through the movie, the other person was on the phone. I am very excited by the film, " Irrfan said.