Director Mani Shankar, who has completed the shooting of his new movie "Mukhbiir" starring Suniel Shetty, Om Puri and Jackie Shroff, says exhaustive research work delayed his film.

"Mukhbiir" is a suspenseful espionage drama that revolves around a young informer.

"It took me four years to make this film because I had to do a lot of research work for 'Mukhbiir'. It is based on a real incident and to convert it into a realistic film, I had to do in-depth study of the subject.

"After that, the selection of stars who could fit into their roles convincingly was another challenge. Like my earlier films, this time also I have a strong star cast," said Shankar.

The film has newcomer Sammir Dattani, who is struggling to find a foothold in filmdom, playing the title role.

When asked him what prompted him to take Sammir, Shankar said: "I found all the qualities in Sammir Dattani which I was looking for. Secondly, if I have selected him out of 200 young artists than there must be something special about him."

His earlier releases "16th December", "Rudraaksh" and "Tango Charlie" bombed at the box office and Shankar is leaving no stone unturned to strike gold at the box office with this one.

He has signed a contract with Zee news for the publicity and promotion of "Mukhbiir".

Produced by Sudhish Rambhotla under the banner of Color Chips Entertainment Media Limited, "Mukhbiir" will hit the screens sometime in September or October.