"There has been an incident and the disciplinary committee are currently analysing the matter," FIFA spokeswoman Delia Fischer told reporters on Sunday.
The media officer being investigated, Rodrigo Paiva, said after the match that there was a scuffle with Pinilla at halftime and that he shoved him in self-defence.
"It was a mess. It was not something only I was involved in. Pinilla came towards me and I only defended myself but I did not punch him."
Pinilla came on after 87 minutes of the last 16 match at the Mineirao stadium just before the match went into extra time. With seconds of extra time remaining, he slammed a shot against the Brazil crossbar.
With the scores level at 1-1 after 120 minutes the game went to penalties and Pinilla missed his during the shootout which Brazil won 3-2 to progress to the quarter-finals where they play Colombia in Fortaleza on Friday.
Image: Mauricio Pinilla
Photograph: Quinn Rooney/Getty Images
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