In a statement, the attorney general said that automated calls from Women's Voices Women Vote that encouraged voters to mail in voter registration forms after the state's deadlines violated state law by failing to disclose who sponsored the call or give contact information.
"Regardless of the motivation, the robo-calls violated the law and they needed to stop," Cooper said in a statement.
The organization told the attorney general's office today that the calls would stop. Cooper's office did not say if the group would face any sanctions for making the calls.
Cooper also urged political parties and campaigns to honor the Do Not Call Registry, although it does not currently cover political robocalls. He encouraged voters with concerns to call the state's telemarketing hotline, 1-877-5-NO-SCAM.
Update: Cooper spokewoman Jennifer Canada said the attorney general's office will continue to investigate the calls before deciding on any sanctions.