A Sydney United 58 fan caught performing a Nazi salute during the Australia Cup final has been slapped with a lifetime ban from the governing body.
NPL NSW side and former NSL club United were the first non A-League Men team to reach the tournament decider.
But their achievement was overshadowed by the behaviour of a section of their supporters as they suffered a 2-0 loss to Macarthur FC at Commbank Stadium on Saturday night.
That included Nazi salutes, a group of fans booing through the Welcome to Country, and the chanting of songs with fascist links.
Some followers of United, formerly known as Sydney Croatia, sang Za Dom Spremni (For Homeland - Ready) -- a chant used by the far-right Ustase movement in Croatia in the 1930s and 1940s -- while others held up questionable banners.
Football Australia (FA) said it had concluded an investigation -- in collaboration with both clubs, their security providers and NSW Police -- into the identified spectator and issued a lifetime ban for the "fascist salute or similar gesture" captured on the host broadcast.
The ban covers all FA-sanctioned football matches, including NPL, A-Leagues, Australia Cup and national team matches.
There could be more bans to come, with FA confirming it is still working with authorities to identify other individuals "who may have committed similar anti-social behaviour."
"What should have been a celebration of a tightly contested and excellent game of football has been marred by the actions of groups of a few people, which do not represent the values and expectations of our football community," FA chief executive James Johnson said in an open letter to fans.
"Their actions have disrespected, hurt, and offended members of our football community."
NSW Jewish Board of Deputies chief executive Darren Bark welcomed FA's action against the fan but expected more to come.
"We cautiously welcome the action taken by Football Australia in handing a lifetime attendance ban to a fan who performed a fascist salute," Bark said in a statement.
"Images on social media show many more fans taking part in these abhorrent acts, including booing the Welcome to Country.
"We look forward to further swift and heavy penalties to be enforced by Football Australia as these fans are identified.
"This behaviour was not only an affront to the Jewish community and the Indigenous community but an affront to all Australians."