PORTLAND -- An investigation is under way into a report of ballot tampering in Clackamas County, but authorities won't say how many ballots might have been altered.
The county clerk, Sherry Hall, said a criminal violation of election law was uncovered by her office Wednesday and reported to the secretary of state's Elections Division.
Hall declined to identify the worker or describe the specific nature of the violation.
Because it's a criminal matter, the Elections Division referred the case to the state Department of Justice.
DOJ spokesman Jeff Manning confirmed the investigation has begun, and it involves a temporary elections worker.
As of Thursday, about 95,500 Clackamas County voters had returned their ballots.
The campaign manager for county Chairwoman Charlotte Lehan, a Democrat, says the alleged fraud has the campaign exploring legal action.