A purge of voters from Wisconsin voting rolls caused problems at the polls for some during this week's primary.

Some voters' information was removed, even though they hadn't moved and it was current. But voters who were not on the poll list could re-register on the spot and still vote. State elections officials say there is no evidence that anyone was prevented from voting.

But the Wisconsin State Journal reports the issue could resurface in future elections that draw bigger turnout. Tuesday's election, which included a Wisconsin Supreme Court primary, drew about 12 percent turnout.

In a statement, the Wisconsin Elections Commission said it is investigating "isolated" reports that some voters had to re-register at the polls before they could vote.

Wisconsin's chief election official, Michael Haas, said the agency is trying to figure out what happened to make sure there are no problems at upcoming elections.

A state initiative last year removed from voting rolls anyone who had moved recently. Such voters either needed to update their voter registration information or -- if they moved out of state -- are no longer eligible to vote in Wisconsin.

However, some voters learned Tuesday they had been removed from registration rolls despite not having moved.

Dane County Clerk Scott McDonnell said Wednesday some voters complained about being incorrectly removed from voter rolls.

State Elections Commission spokesman Reid Magney said Wednesday that the agency also had heard some of those complaints. He apologized for any inconvenience.

As part of last year's initiative, about 343,000 postcards were mailed in November to Wisconsin voters flagged by the Electronic Registration Information Center, a multi-state group that uses state and federal data to identify voters who may need to update their registration.

Those who didn't respond to the postcards were removed from the voting rolls, Magney said. He said it's not yet known how many voters were removed from voting rolls despite not having moved.

Magney said the commission has not heard from anyone who was not able to vote Tuesday. Wisconsin law permits same-day voter registration, so anyone whose registration information was purged could update it at their polling place, provided they could supply a proof-of-residence document.