Was it something he said?
With France and Italy tied in overtime in Sunday's World Cup final, Zinedine Zidane head-butted Marco Materazzi in the chest and was ejected. France went on to lose in penalty kicks.
The day after, no one seemed to know what the Italian defender might have said to the French star.
"The Italians did everything they could do to provoke Zidane," France defender William Gallas said.
Seconds before, Materazzi had grabbed a handful of Zidane's jersey just as a French attack on goal passed harmlessly by. The two exchanged words as they walked back up the field, well behind the play. Then Zidane spun around, lowered his head and rammed Materazzi, knocking him to the ground.
The Paris anti-racism advocacy group SOS-Racism issued a statement Monday quoting "several very well-informed sources from the world of football" as saying Materazzi called Zidane a "dirty terrorist." It demanded that FIFA, soccer's world governing body, investigate.
FIFA, which reviews all red cards at the World Cup, would not comment on the specifics.
Materazzi was quoted as denying the terrorist comment.
"It is absolutely not true, I didn't call him a terrorist, I don't know anything about that," the Italian news agency ANSA quoted Materazzi as saying when he arrived with his team in Italy.
"What happened is what all the world saw live on TV," the Italian player said.
Zidane's agent, Alain Migliaccio, was quoted by the BBC as saying the France captain told him the Italian "said something very serious to him, but he wouldn't tell me what."
Even with the ejection, Zidane still won the Golden Ball as the World Cup's best player.
Italy's triumphant World Cup squad returned home Monday evening to celebrate with its fans.
Team captain Fabio Cannavaro, clutching the golden trophy, was the first to emerge from the chartered plane that brought the team from Germany. Acrobatic air force planes streaked overhead, coloring the sky with streams of red, white and green smoke -- hues of the Italian flag.
Cannavaro hoisted the trophy in front of about 500,000 during a victory rally at Circus Maximus, an area for entertainment in ancient Rome.
The World Cup final earned a 7.0 fast national rating for ABC, a 180% increase from the 2002 final in Japan.
A ratings point represents 1,096,000 households, or 1% of the nation's estimated 109.6 million TV homes.
Juventus, the Serie A soccer power at the center of the Italy match-fixing scandal, hired former midfielder Didier Deschamps as coach.
Deschamps, captain of France's World Cup-winning team in 1998, replaces Fabio Capello, who resigned last week to coach Real Madrid.