Brazil star Neymar is at the centre of a racism row after a banana was thrown on to the field during his country's 2-0 victory over Scotland at the Emirates Stadium.
The alleged incident took place as the 19-year-old was preparing to take a penalty to score his second of two goals during Sunday's match.
Speaking afterwards, Neymar accused some spectators of racially abusing him, a claim also made by team-mate Lucas Leiva, who television pictures reportedly showed retrieving the banana.
Neymar said: "I feel great and scored two but what happened with the banana is sad. I don't want to make a big deal of it. I was running down the touchline in the second half and saw it but I didn't see where it came from.''
Santos forward Neymar, who has been strongly linked with a move to Chelsea, said on Brazilian television channel Sportv: "They were jeering me a lot, even when I was about to kick the penalty. The entire stadium was jeering. This atmosphere of racism is totally sad.
"We leave our country to play here and something like this happens. It's sad. I'd rather not even talk about it, to keep the subject from escalating.''
Sunday's match was played at a neutral venue in England and it is unclear whether the banana was thrown by a supporter of either side or a neutral.
The Scottish Football Association have strongly refuted claims that Scotland fans - the Tartan Army - had any involvement and a spokesperson said: "There has been no such incident reported to the police or the stadium safety officer. In fact, the tens of thousands of Scotland supporters who travelled to the Emirates were commended for their behaviour.
"The Scotland supporters are known the world over for their impeccable behaviour and we have no reason to believe that, after speaking to the relevant authorities, they have been anything other than exemplary.
"The Scotland fans helped create a wonderful spectacle inside the Emirates and throughout London and should be applauded for their support.''
Neymar's Brazilian team-mate Lucas, who plays his club football at Liverpool, said: "There is no more space for racism in the world. They say it's the first world here in Europe, but it's where it happens the most. That has to change. Everybody is equal today. It's a matter of respect.''
Brazil manager Mano Menezes and Scotland boss Craig Levein both denied any knowledge of the incident. Menezes said: "If it happened, that would be lamentable but it has not been confirmed yet.''
Tartan Army spokesman Hamish Husband strongly denied the jeering of Neymar was racially motivated. He said: "The reason Neymar was booed was because we believed he was feigning injury. Racism has no place in the Tartan Army, and if it did, it would be stamped out immediately, because we are self-policing.
"Any suggestion of racism from the Tartan Army today, as far as I am concerned, is absolute tosh. We accept that Brazil played us off the park, and we applauded them for that.''