Arizona Corporation Commissioner Bob Stump repeatedly communicated with the executive director of a “dark money” group that spent hundreds of thousands of dollars to help elect the candidates he backed, while also keeping regular contact with those candidates, their campaign manager, and a senior executive of the state’s largest utility, Arizona Public Service, according to recently released records.

The links to Stump, who was the Commission chairman at the time, come to light in the form of text message metadata obtained by Checks & Balances Project, a Washington, D.C.-based 501(c)4 non-profit organization that advocates against regulatory capture and on behalf of renewable and sustainable energy policies.

The text message logs come three months after a whistleblower complaint made by a Commission staff member alleged that Stump and former commissioner Gary Pierce facilitated electioneering from inside the commission. The Arizona Attorney General is still investigating those claims.

While the text metadata include the phone number and time and date of each text, they do not contain the text message content. Checks & Balances Project Executive Director Scott Peterson said there’s now a strong case for obtaining the content of the texts in order to see if they contain indications of improper activity. Peterson said he and his attorneys are exploring the option of a subpoena to do so.

Stump said the texts demonstrate that he has made himself accessible to stakeholders and constituents, not inappropriate activity. His cell phone is paid for by the commission.

Stump’s text metadata show that between May 1, 2014 and the March 11, 2015, he traded 100 text messages with Scot Mussi, executive director of the Arizona Free Enterprise Club. The group spent roughly $450,000, aimed at helping elect Tom Forese and Doug Little, Republicans whom Stump also publicly supported.

More than three-quarters of all the money spent in the race came from 501(c)4 nonprofit organizations, such as Arizona Free Enterprise Club, which are not required to disclose their donors. And all of the “dark money” spending went toward helping Forese and Little.

During the same timeframe, Stump texted with Little 192 times, with Forese 51 times, and with their campaign manager Alan Heywood 21 times.

He also exchanged 56 texts with Barbara Lockwood, Arizona Public Service general manager of regulatory policy and compliance, while APS had pending business in front of the commission. Stump said in an email that the communications were only ordinary business.

He also said he and Mussi have been friends for nearly 15 years, that the two have had lunch on several occasions over the past year and that the communication between the two is nothing but correspondence between him and a friend.

“I would never have engaged in any inappropriate discussions regarding Scot’s political work,” Stump wrote.

Mussi did not respond to phone calls and emails for comment.

Heywood said that he doesn’t recall what the text message conversations between him and Stump concerned, but said that they wouldn’t have been about campaign spending coming from Mussi’s group supporting Forese and Little. Heywood said other candidates whose campaigns he managed were the subject of “vicious and ugly attacks” from Arizona Free Enterprise Club.

“I don’t believe I’ve ever met Scot Mussi or ever talked to Scot Mussi… I have no idea what Bob was talking to him about or if he was,” Heywood said. “I’m not sure what we would have been texting about back on July 25, but it would have had nothing to do with Free Enterprise Club or Scot Mussi.”