Ronaldo in hot water for pulling hair
The incident happened as he tussled with Botafogo midfielder Fahel in Sunday's goalless draw in the Brazilian championships.
"We've requested the video of the match and on Thursday I am going to analyse it and see if there was an infringement," said Paulo Schmitt, an official with Brazilian football's disciplinary tribunal.
"I've never seen hair pulling in a football match," he told the tribunal's website.
Fahel said he complained to Ronaldo about the incident during the game but did not bear any resentment.
Ronaldo has scored eight goals for Corinthians in his latest comeback following last year's knee injury with AC Milan.