(CNN) - The New Hampshire Attorney General's office is investigating whether Democratic Senate hopeful Paul Hodes ran "push polls" intended to cast a potential rival, Republican candidate Kelly Ayotte, in a negative light.
The phone calls in question hit New Hampshire households last week and raised questions about Ayotte's handling, when she was Attorney General, of a mortgage firm at the center of a Ponzi scheme that defrauded investors. The Hodes campaign had previously run television ads attacking Ayotte on the topic.
But according to state law, polling calls "which state, imply or convey information about the candidate's character, status or political stance or record" are considered push polls and punishable by fines or jail time.
The calls prompted the state Republican Party to file a complaint Monday with the Attorney General's office, which is now looking into the matter.
New Hampshire GOP spokesman Ryan Williams called the polling calls "dirty campaign tactics" and "gutter politics."
"These unethical push poll calls clearly violated state law and attempted to smear his opponent with lies and distortions," Williams said in a statement.
The Hodes campaign has not admitted to conducting the controversial poll, but denied any smear tactics.
"All of our polls are lawful and conducted for statistical purposes only, not to disseminate messages," said Hodes spokesman Mark Bergman. "We don't comment on the specific timing or content of any market research we conduct. This is just another partisan stunt from the New Hampshire Republican Party."
Hodes has trained his fire on Ayotte in recent weeks, but she still has to survive a four-way primary on September 14 for the nomination. Her main rival for the GOP nod is millionaire businessman Bill Binnie.