GREENVILLE — South Carolina election officials say they still plan to use touch-screen voting machines despite the fact that other states have banned the use of similar systems made by the same company.

Last month, top election officials in Ohio and Colorado declared that Election Systems and Software's iVotronic is unfit for elections.

The ban was prompted by a study done for the state of Ohio in which researchers found electronic voting systems could be corrupted with magnets or handheld electronic devices such as Palm Treos.

"We've reviewed the report and we remain confident in the security and accuracy of South Carolina's voting system," state Election Commission spokesman Chris Whitmire said.

But the South Carolina League of Women Voters has renewed its call for the state to record votes on paper as well as electronically to allow for accuracy checks, though there have been no documented cases of actual election tampering.

"It's very difficult to get evidence that somebody tampered with the vote if you have no way of knowing what the vote was before they tampered," said Eleanor Hare, a computer scientist who participated in a study of the machines by the South Carolina League of Women Voters.

The machines have been used statewide since 2006.

The Ohio study found the machines "lack the fundamental technical controls necessary to guarantee a trustworthy election under operational conditions."

"Exploitable vulnerabilities allow even persons with limited access — voters and precinct poll workers — to compromise voting machines and precinct results, and, in some cases, to inject and spread software viruses into the central election management system," the report says.

However, the company that makes the machines says on its Web site that it disagrees with the Ohio report's technical findings.

"All of our voting systems have been thoroughly tested and examined under realistic election conditions before those systems are ever made available to states for additional testing and consideration," the company's statement says. "The testing and certification processes already in place are extremely rigorous, ensuring that voting systems meet well-established standards for performance under realistic election conditions."