Former Everton favourite Tim Cahill is facing the threat of a World Cup ban and a huge fine as the furore over his Australia goal celebration rumbles on.

FIFA are reportedly poised to investigate the manner in which Cahill marked the matchwinner in his country's 2-1 play-off win over Syria on Tuesday.

Cahill, who normally celebrates scoring with a trademark 'boxer' gesture at the corner flag, made a T symbol above his head after netting the decider during extra time in Sydney.

It has since emerged Cahill was seemingly promoting travel outlet TripADeal, for whom he is an ambassador, with the company thanking him after the game.

In a post later deleted, they wrote on Instagram: “Did you catch @tim_cahill, our new brand ambassador, doing the TripADeal 'T' after he scored the winning goal last night? Congratulations Tim!'”

Social media reacted with almost universal disdain, and FIFA are now believed to be looking into the celebration and whether Cahill was paid to make the gesture.

Tim Cahill and his already notorious celebration
Tim Cahill and his already notorious celebration

The world governing body take a dim view on such stunts, with their regulations stating players cannot wear undergarments that show political, religious or personal slogans, statements or images.

But while Cahill's was a physical gesture rather than an item of clothing, he could face similar censure to Nicklas Bendtner, who in 2012 was fined £80,000 and handed a one-match international ban for revealing underwear sponsored by Irish bookmaker Paddy Power when celebrating a goal at the European Championships.

If Cahill receives a one-match ban, it would rule him out of the first leg of Australia's final World Cup qualifying play-off against Honduras next month.

Australia's football association, however, will not take action against the midfielder.

"We don't believe Tim's breached any laws," insisted a Football Federation Australia spokesman, speaking to the BBC. The FFA also said they have not been contacted by FIFA about the matter.