Top Republican legislators want an independent review of Minnesota Secretary of State Mark Ritchie's move to allow online voter registration.

In a letter to Legislative Auditor Jim Nobles on Monday, four prominent GOP lawmakers accuse Ritchie of using "dubious authority" to set up the system without explicit legislative permission.

Last month, Ritchie's office announced the launch of the system that can be used by new registrants or those looking to update their existing registration. In seeking the review, the Republicans say they want ­assurances of data safeguards.

People using the system must present verifiable identification information and they'll have their applications checked in similar fashion as before. Successful applicants will be notified of their polling place.

Neither Ritchie's office nor Nobles immediately returned messages about the inquiry request.