The state executive of the NSW Liberal Party has started suspension proceedings against a wing of the party following an extraordinary brawl outside an Arncliffe chicken shop, as well as appointing a private investigator to examine the incident.

Documents obtained by Fairfax Media also reveal the full extent of the allegations surrounding the meeting, including an elderly woman being trampled, mobile phones being destroyed and culprits fleeing the police.

Members of the state executive - including Prime Minister Malcolm Turnbull's representative Paul Fletcher and Premier Gladys Berejiklian's proxy Matt Kean - voted 18 to nil on Wednesday to start suspension proceedings against the Bayside Local Government Conference.

Screenshots of footage taken from a brawl that erupted during a Liberal Party branch meeting outside a café in Arncliffe on Monday. Credit:Seven News

If the suspension is confirmed - which sources said was inevitable - it would mean the branch can't run Liberals for election to Bayside Council, and can't hold meetings or raise funds.