Football Australia on Sunday promised strong and swift action after the Australia Cup final was marred by "anti-social behaviour" from supporters.
Over 16,000 fans were in attendance at Western Sydney Stadium on Saturday for the soccer final as Macarthur FC recorded a 2-0 win over semi-professional outfit Sydney United 58.
According to reports in Australian media, fans chanted and booed during the Welcome To Country ceremony.
Pictures on social media also appeared to show Nazi salutes being performed by supporters of Sydney United 58, who were founded as Sydney Croatia in 1958 and were a powerhouse in the National Soccer League that preceded the formation of the A-League in 2004.
Football Australia said it condemned the behaviour of a "small minority of individuals."
"Football Australia is today assessing all footage and images available of certain individuals which are of concern to our organisation and the broader Australian football community, including the displaying of the 'Hitler salute'," the country's soccer governing body said in a statement on Sunday.
"Football Australia is working closely with the management of CommBank Stadium and New South Wales Police to determine strong and swift action on any identified anti-social behaviour, which may also be deemed as illegal in the state of NSW.
"Football Australia will be holding discussions with Sydney United 58 FC about the behaviour of certain fans, which could lead to both individual and club sanctions."
Earlier on Sunday, Professional Footballers Australia co-CEOs Beau Busch and Kathryn Gill said "universal values of fairness, respect and courage" had been "shattered."
"Our sport must now respond and the players are committed to playing an important role," Busch and Gill said in a statement. "An effective response will not be developed by focusing on whether or not these actions were inflicted by a minority."
Former Sydney United and Australia player Craig Foster tweeted: "All involved need to be held accountable including the club."
