Washington — The FBI executed a search warrant at the office of an Ohio-based community grassroots group known for its voter registration work as part of an ongoing fraud-related investigation, multiple sources familiar with the matter told CBS News.

The target of the search, the Ohio Organizing Collaborative, is a civil rights organization that works to register voters and advocates for criminal and economic justice reform.

Around the same time the search warrant was executed on Thursday, federal agents also started showing up at the homes of employees and volunteers to interview them as part of the probe, said Prentiss Haney, a board member of the Ohio Organizing Collaborative who was authorized to discuss the matter for the group.

The search, and the attempts to interview people affiliated with the group, were reported earlier by MS Now.

Haney said that the questions from the agents appeared to be focused on voter fraud.

Haney called the law enforcement operation an "assault" against civil rights groups that work to engage people in the democratic process.

He said there were "over 125 agents" who went to the homes of volunteers, civil rights leaders, community leaders and staffers. 

"They were following people in their cars. Following kids to school. They were knocking on doors. Calling the phone. Demanding to come into houses to get phones without warrants," he said.

A DOJ official declined to discuss the details of the Ohio case, saying the search warrant affidavit remains under seal.

"Search warrants are authorized by a judge and anything said by any organization or others in the media is unfounded speculation, as the target of any investigation is not privy to the search warrant affidavit until after the indictment," the official said in a statement.

The questions from the agents about voter fraud come at a time when the Justice Department has more broadly sought to investigate cases of voter fraud across the United States in the lead-up to the midterm elections.

Earlier this year, for instance, Minnesota's secretary of state received grand jury subpoenas seeking a limited number of individual voter records as part of a federal investigation into whether noncitizens are registered to vote or have unlawfully cast ballots.

The FBI also recently attempted to interview the director of elections in Milwaukee County, Wisconsin.

Meanwhile in California, prosecutors last month announced criminal charges against a Los Angeles-area woman who was accused of paying homeless people to register to vote.

The Ohio Organizing Collaborative over the years has received donations from progressive groups such as New Venture Fund and the Tides Foundation, according to tax records filed with the IRS. Both of those groups have received scrutiny in the past from Republicans over financial mismanagement allegations.

In 2017, a paid canvasser for Ohio Organizing Collaborative pleaded guilty for involvement in a fraudulent voter registration scheme.

Another donor to the group has been the Voter Registration Project, which was previously accused by the conservative-leaning Capital Research Center of violating its nonprofit status by leading an effort to register millions of voters who helped Joe Biden win in 2020, tax records show. The project has denied any impropriety, though the allegations prompted Republican lawmakers in Michigan to request an investigation by the Justice Department in 2025 "to determine the extent of their involvement in illegal electioneering activities and fraudulent voter registration efforts."