The inquiry by Rep. Elijah E. Cummings , a Democrat, is being started a week after Sen. Barbara Boxer (D-Calif.) urged the Justice Department to enforce voting rights laws, citing a Los Angeles Times article detailing attempts by an Ohio offshoot of the group, True the Vote, to strike hundreds of students and others from voting rolls.

“At some point, an effort to challenge voter registrations by the thousands without any legitimate basis may be evidence of illegal voter suppression,” Cummings told True the Vote founder Catherine Engelbrecht in a letter on Thursday. “If these efforts are intentional, politically motivated and widespread across multiple states, they could amount to a criminal conspiracy to deny legitimate voters their constitutional rights.”

Cummings is the ranking minority member of the House Committee on Oversight and Government Reform.

Engelbrecht, a Texas tea party leader, has described True the Vote as an effort to prevent election fraud and clean up voter registration rolls. The group recruits volunteers, largely through tea party networks, to scour voter lists, challenge the registration of those they believe are dead or do not live at their listed address, and monitor the polls on election day.

“True The Vote has forwarded Congressman Cummings’ letter to its legal team and is more than happy to avail itself” to the congressional committee, the group’s spokesman, Logan Churchwell, said by email. “In the interim, True The Vote invites Congressman Cummings, or any other interested parties, to participate in any training sessions in the weeks ahead.”

The Times article described efforts by the Ohio Voter Integrity Project, a spinoff of True the Vote, to remove more than 2,100 names from voter rolls. Hundreds of them were college students the group tried to strike from the rolls for failure to specify their dorm room numbers. Local election boards declined to remove any of them.

The Ohio group also challenged the rights of eight members of an African American family to vote from an address it identified as a vacant lot outside Cincinnati. But the address was actually the house where the family had lived for nearly three decades. The family suspected race was the group’s motive. The white tea party activist who challenged the family said she had made a mistake and apologized.

In a statement dated Monday on True the Vote’s website, Engelbrecht said the group’s Ohio volunteers had no intention of challenging properly registered voters and were “completely unprepared for the partisan gamesmanship and media spectacle they were subjected to.”

“They trusted in the system and were betrayed at every turn,” Engelbrecht said. “True the Vote stands by the well-intentioned efforts of these citizens and is disgusted by the attempts of some within government and media to warp what should have been a simple, legal process into a calculated partisan charade.”

In his letter, Cummings expressed concerns about the Ohio voter challenges, as well as others reported in North Carolina, Wisconsin and Maryland. He asked True the Vote to provide information “about the data you have been using to challenge voter registrations, the training you have been providing volunteers to conduct these activities, and the manner in which you have been determining where to deploy your resources in select jurisdictions.”