Cahill celebrated his winner by making a 'T' sign with his hands, which Australian online travel agency TripADeal later thanked him for on social media.
"Did you catch @tim_cahill, our new brand ambassador, doing the TripADeal 'T' after he scored the winning goal last night? Congratulations Tim!" the Instagram post read.
A FIFA spokesman has now confirmed via Sky Sports News that the celebration is being looked into.
"FIFA is reviewing and analysing the reports from the referees and the match commissioners for all matches in FIFA competitions," the spokesman said. "Events which require further attention may be communicated accordingly."
Niklas Bendtner was previously fined £80,000 by UEFA in 2012 for exposing underwear showing the brand of a betting company .