SOUTH BEND -- An investigation is underway after thousands of allegedly fake voter registration applications were sent to Lake County.

Indiana Secretary of State Todd Rokita says he has "credible evidence" of voter fraud involving ACORN. It's a community-based organization that helps register low-income people.

That same group also dropped off dozens of voter registration applications in St. Joseph County on Monday.

Officials don't know if any of those are fraudulent because they haven't been processed yet. Rokita says protecting voters and taxpayers is most important.

He spoke to WSBT News while attending the 3rd annual Medicine Ball in South Bend Saturday night.

"What I'm asking the St. Joseph County election board to do is to notify us if they see something that they believe is fraudulent. And I will be up here with my investigators to secure the material, get copies and we will treat St. Joseph County as we have treated other Indiana counties in terms of attention on this matter," said Rokita.

St. Joseph County officials hope to have voter registration applications processed by the end of next week.