A footy fan appears to have spat onto spectators at Marvel Stadium on Saturday night as the ongoing debate about crowd conduct roars on.

Two male footy fans were filmed on the top level of the stadium joking together before one spat onto fans below after the Brisbane Lions and St Kilda Saints clash.

"Nice fans spiting onto level 2," Saints supporter Brett Stirling wrote on Twitter when he posted the video.

Mr Stirling said the spitting happened after the game, when fans had begun filing out of the stadium. He believes the top level was likely empty apart from the two men.