According to the Los Angeles Times, auditors didn't find any evidence of wrongdoing in Bell during the time when several city leaders are alleged to have been involved in corruption scandals.
A spokesman for Mayer Hoffman said examining city leaders' salaries wasn't the auditors' job. He also questioned whether they were given accurate information from the city.
Mayer Hoffman does outside audits for several California agencies.
The state controller's office is expected to release its own report on the firm by the end of the year.
The Associated Press contributed to this report.