European anti-racism body Fare filed a complaint to Fifa over the issue.
But, while the FA does not dispute reports that the chanting took place, it has failed to find any proof. This follows reports that an offensive song was aimed at the brothers by supporters of their own country during England's win in San Marino.
"We've been asked to supply our submission to Fifa by Tuesday, which we will do," said FA managing director of Club England Adrian Bevington.
"We have gone through all of the video evidence that our security team recorded on the evening of the game.
"I do want to make clear that while the journalists who have reported this have done so in good faith, they clearly have heard some chanting of a particular nature, and we're not disputing that, but we haven't been able to identify any of that from the recorded evidence that we've gone through."
Football Against racism in Europe (Fare) did not have its own observers at the World Cup qualifier on Friday, 22 March and said it had pulled together evidence, including "media comment".
The English authorities will be hoping this is the end of the matter, but if Fifa were to pursue the matterfuture sanctions are possible, but at this stage seem unlikely.