John Abraham said he met classmates of Manya Surve and the then ACP Isaque Bagwan who was in the hit squad that took out the gangster in 1982.
"We had Hussain Zaidi (journalist and writer) on the sets of the film and he guided us pretty well. There are only two file photos of Manya Surve -- a passport size photo and after the encounter there was another picture of him... What we could learn from photo is his look", he said.
John said Surve was a ruthless gangster who did not spare even his classmates.
"We spoke to Isaque Bagwan (in the film the character is played by Anil Kapoor) who gave us a lot of information. We did extensive research on Surve. He was a body builder, tough and ruthless. We also met his college friends and his classmates. In 1979 to 1982 he was ruling Bombay. He did not spare his classmates", the actor said.
John said the action in Shootout at Wadala was rough and real unlike the monkey kind of action displayed in contemporary films.
"I did Race 2 where there were good and interesting action sequences... I think after Ghayal the raw and real action is performed in the Shootout.... Today, we see a lot of kung fu, monkey kind of action where people fly and all. But the action in this film is real", he said.
Responding to a query John said that marriage of Underworld and Bollywood was long over with the entry points of black money into the industry becoming redundant.
"When I came in 2003, most of it (Underworld) was cleared... There was nothing like that. I have not experienced any such thing. We deal in white money. We don't have black money as we are paid by corporate ventures. The underworld thing did not happen to me in my life and I am happy about it.
"I don't think it exists anymore in Bollywood", the actor added.