Mumbai, Mar 20 (IANS): Filmmaker Hansal Mehta says that to make his film "Omerta", which is based on terrorist Omar Saeed Sheikhs life, as authentic as possible, he purchased real-life footage from a number of sources.

Footage of the Kandahar attack, media footage following the 9/11 attack in the US and other clips were acquired from a whole range of sources by the film's team.

"When it comes to the film, everything has to be credible. To ensure we kept it as real as possible, we purchased the actual footage. The film covers various crucial events from world history. I had to buy these videos from different agencies. They were bought in bits and pieces through the years," Mehta said in a statement.

"Omerta" was shot in real locations across London and India. It is woven around some of the most bloody terror attacks, including the 9/11 attack and the beheading of journalist Daniel Pearl.

Presented by Swiss Entertainment and Karma Media, produced by Nahid Khan and directed by Mehta, "Omerta" stars Rajkummar Rao. It will release on April 20.