TULSA COUNTY, Oklahoma - With only a week remaining until the primary election, the Tulsa County Sheriff has taken a turn for the negative.

Republican candidate Luke Sherman released an attack ad against current Sheriff Vic Regalado, calling his ethics into violation.

It's only aired a few times so far, but the commercial makes an impact.

"Don't let another elected official fail our Oklahoma standards," the ad says, referring to Regalado.

The ad cites a Tulsa World article that says the Oklahoma Attorney General is investigating a group of donors who gave money — possibly illegally — to Regalado during the special election.

The commercial, though, says Regalado is the one being investigated: "Regalado is under investigation by the Attorney General for taking illegal donations to his campaign," the ad says.

Regalado's campaign says that's not accurate. But Sherman stands by the claim.

"We can split hairs all we want, but you are your campaign," Sherman said. "We wouldn't be here if it wasn't for those questionable donations being taken and spent by that campaign.

A spokesperson for the Oklahoma Attorney General's Office would neither confirm nor deny they are investigating donations made to Regalado's campaign, saying they don't typically release that information.

When asked for comment, Regalado released this statement to News On 6:

"Once again, my opponent is running a false and negative campaign in the closing days of an election. His ad is completely untrue, designed only to slander and defame my name so he can score political points. A candidate who will say anything to win is not someone voters should trust."