Public prosecutor Luis Cevasco told the TN cable news channel he was studying Sunday's incident when Riquelme ran 50 metres to point his finger at a supporter.
"In principle he has violated two rules," Cevasco said on Monday. "One which concerns affecting the progress of the match and another which concerns inciting disorder.
"We have to verify the motive and the gestures," he said, adding the offences could yield fines or up to 10 days in custody.
Early in the second half Riquelme appeared to be involved in an altercation with the supporter who was sitting only metres from the touchline in Boca's tightly-packed Bombonera stadium.
"I didn't do anything bad," Riquelme said in a television interview. "I just shouted when my team scored a goal.
"There are people who pay to get in and think they can insult us for two hours."
"So many things go on in this country and I think it's daft to talk about this matter."
