Heather Holt, the Ethics Commission's director of policy and legislation, said elected officials who accept tickets to events to perform a ceremonial function must disclose it and keep a record for four years.
Members of the commission asked if that meant an elected official who presented a plaque during the halftime ceremony at a Lakers game should be barred from watching the rest of the game. Holt said, "We believe that one of these types of admission tickets from restricted sources can affect the public's perception of the integrity of the city's decision-making processes."
The state's Fair Political Practices Commission is also conducting an investigation into Mayor Villaraigosa's acceptance of free tickets.
The Los Angeles County District Attorney's Office has opened a preliminary inquiry into the matter as well.
City News Service Contributed to this story.