The controversy comes as new Republican backed voting requirements to prevent fraud face legal challenges.
More than 100 voter registration applications from Palm Beach County, Florida are at the center of the case against strategic allied consulting.
"There were a lot of signatures that appeared to be--possibly--common, and there was a lot of missing information," explains Palm Beach County Election Supervisor Susan Bucher.
The state attorney's office is now investigating Strategic Allied Consulting.
The firm has replaced its website with a statement indicating the person responsible has been fired, and with a link to their employee training video.
According to the firm, it's held voter drives in 40 different states, including five key battleground states: Florida, North Carolina Colorado, Nevada and Virginia, where the Republican party paid the company nearly $3 million to register voters.
"Republicans do have some egg on their face. They fired this organization as soon as these allegations came to light, so they are obviously sensitive to the fact they have made similar allegations against the Democrats," notes Michael McDonald of the United States Election Project.
Recently, Republicans have passed laws in more than a dozen states to combat fraud at the ballot box.
In Pennsylvania, a judge has less than 24 hours to decide whether to uphold a law requiring voters to have photo IDs for this election.
A representative for the Florida State's Attorney's Office says the investigation could take weeks.
They're trying to determine how many people may have been impacted and whether they will press criminal charges.