According to police, around 2 pm the assailants shot Raju Shinde (45), an office-bearer of Shiv Sena's film wing 'Chitrapat Sena', who was sitting on a chair under a tree. He was immediately taken to Nanavati Hospital.
Shinde owns Trinity security agency, which provides security guards for film shootings.
Mumbai police have formed four teams to nab the assailants while the crime branch too has started a parallel investigation.
Shinde's condition was stable. He received two bullets injuries in abdomen and one on the right hand.
"We have seized the motorcycle and it seems it was not stolen, so we are hopeful of getting vital leads soon," added Patil.
When asked whether Shinde was really facing a threat to his life as he had reportedly approached the Mumbai police in January seeking protection, Patil said, "Our investigation is on and would include all possible angles."
Kunjuraman had written the letter on Shinde's behalf, he told PTI.
Immediately after the incident, Bachchan tweeted that he was 20 feet away from the spot where the incident took place and one person had died.
Later he clarified that the person was not killed but injured.
"Correction: in gang shoot out where I was shooting in Film City person shot at is NOT dead. He has been taken to hospital," the Big B tweeted.
