A lawsuit from Indiana voter advocacy groups alleges a new state law that allows counties to purge inactive voters from their rolls violates federal law. The legal action was brought on behalf of Indiana’s NAACP and the League of Women Voters.

For years, Indiana’s used what’s called the Interstate Voter Registration Crosscheck to look for voters who moved to another state. Legislation that took effect July 1makes it easier for counties to remove voters found in that system.

But the Brennan Center for Justice raised concerns about the law in May in a letter to Secretary of State Connie Lawson. The center says the crosscheck system is flawed – it notes Virginia experienced error rates as high as 17 percent when it used the system in 2013.

And Brennan Center attorneys say federal law still requires counties to contact voters before they’re eliminated from the rolls.

But the center says nothing happened after it sent the letter to Lawson, which prompted a lawsuit to strike down the new state law.

Lawson’s office says it does not comment on pending litigation.