Five days after the shootout near the chief minister's Palm Avenue residence, the intelligence branch on Thursday moved to prepare a dossier on the gangs operating in the area.
A letter from additional director-general of police Sujit Sarkar, seeking the details, reached Karaya police station during the day.
Police have learnt that Sheikh Anwar pulled the trigger on Firoz Khan over rights to supply building material to several housing projects in the area. Khan, who has criminal antecedents, had bagged the supply contract for a project on Ballygunge Park Road. Anwar wanted a share, which led to the shooting.
Police said that generally, local people supply the building material for construction projects in the area.
According to police, some associates of Firoz, including Asgar, Asraf and Chinar, had bagged on his behalf the supply contracts for some of the housing projects in the area, prompting his rivals to react strongly.
'There was no major outburst, since the most notorious operators are behind bars,' said a police officer.