FIFA is investigating claims Brazil's press chief Rodrigo Paiva hit Chilean player Mauricio Pinilla during the World Cup last 16 game between the two countries, a spokeswoman said Sunday.
The incident happened at half-time in Saturday's match which Brazil won on penalties.
Chile's media spokesman Maria Jose said his Brazilian counterpart "hit" Pinilla.
Paiva told Brazilian media there was shoving by both sides as the two teams left the field.
"I was not the only one involved. Pinilla came looking for me and I just defended myself," he was quoted as saying.
"I just pushed him," he added.
"They started to insult us, there was some shoving but no assault," Paiva said.
Television showed images of a tense face-off between Brazil striker Fred and Chile's Gary Medel just before the incident.
FIFA spokeswoman Delia Fischer told a briefing that the governing body's disciplinary commission was looking into the alleged punch.