The video that emerged on Monday allegedly shows the 30-year-old running in from out of frame before appearing to lash out at another man with a wild kick.
The Daily Telegraph reports Walker was recovering from shoulder surgery at the time and was unable to use his arms as he attempted to separate two men in the middle of an alleged dispute.
It follows revelations Walker's management was unaware of the existence of the video.
Daily Telegraph reporter Phil Rothfield told Sky Sports Radio on Monday agent Matt Rose only became aware of the alleged incident on Saturday when Walker is reported to have received a phone call as part of an alleged extortion plot.
The Rabbitohs said in an initial statement Walker's involvement in the alleged incident was never the subject of a police investigation until the star came forward to reveal the alleged blackmail plot.
"The South Sydney Rabbitohs are aware of an incident involving player Cody Walker which took place in northern New South Wales in October 2019," the club statement read.
"The NRL's integrity unit have been informed.
"At no stage has Cody Walker been the subject of a police enquiry in relation to this incident."
The Rabbitohs said that the enquiry had been instigated by Walker himself. The NRL has confirmed that integrity unit has been informed.
