RALEIGH, N.C. (AP) — Federal investigators in North Carolina are seeking an enormous number of voting records from dozens of state and local election offices weeks before the midterm elections.

Documents and the state elections board confirmed the U.S. Attorney's Office in Raleigh issued subpoenas recently on behalf of Immigration and Customs Enforcement to the state board and local boards in more than 40 counties. Their requests — which the state elections board estimates would cover well over 20 million documents — may signal their expanded efforts to prosecute illegal voting by non-U.S. citizens.

The same federal prosecutor, Bobby Higdon, announced two weeks ago that 19 foreign nationals were charged with registering to vote or casting ballots illegally because they weren't citizens. His office had no comment Wednesday.