The center of the investigation focuses on the 2005 elections, where about 400 voters cast ballots - most of them absentees - to approve a measure that allowed the high salaries to top city administrators to be paid out.
Some residents say city officials urged them to sign up for absentee ballots, but when they went to the polls to vote, they discovered their votes had already been submitted.
"If, in fact, the election itself has been tainted by improper electioneering or other violations of state law, then that involves civil, maybe even criminal, penalties, and in some circumstances, you can overturn the election itself," Brown said in a news conference on Monday.
Brown is hoping to depose the city officials over the next two weeks.
"The possibility that maybe we can go back and undo that election and start to justify the wrongs starting back then and move forward would be great," said Cristina Garcia of the Bell Association to Stop the Abuse. "We hope that gets pushed a little harder. It cheated the candidates, it cheated the community."
Brown also set up a hotline to report voter fraud and other problems. Voters can call (866) 625-4400 if they suspect voter fraud.