Democrat Kitzhaber, in a letter dated Monday, asked Attorney General Ellen Rosenblum, also a Democrat, to investigate the matter. The attorney general responded that a probe was already under way.
"My office has already opened an investigation into this matter. I appreciate your intent to fully cooperate,” Rosenblum said in a letter to the governor.
Kitzhaber, who was re-elected to an unprecedented fourth term in November, has been dogged for months by mounting allegations that fiancée Cylvia Hayes used her role in his office for personal gain.
It was not immediately clear when Rosenblum, who last week characterized the allegations against the governor as troubling, had opened the investigation. Neither her office nor the governor's would respond beyond the letters.
The probe by the attorney general's office appeared to be in addition to a review by the state's ethics commission of whether Hayes’ acceptance of consulting contracts may have violated state ethics rules.
The state's flagship newspaper, The Oregonian, last week called on Kitzhaber, whom it had endorsed for re-election last year, to resign. Kitzhaber has said he has no plans to step down, and promised to cooperate with the attorney general's probe.
"I deeply regret that this situation has become a distraction from the important work of our state and look forward to your review and its conclusions," he said in the letter.
Adding to woes facing the governor, media reports last week revealed that Hayes received $118,000 in previously undisclosed consulting fees in 2011 and 2012 from the Washington-based Clean Economy Development Center while advising the governor on energy policy.
Kitzhaber did not disclose Hayes’ income from the Clean Economy group on his annual economic interest statements despite disclosing other fees she had received via consulting contracts. He has said the couple did not see it as a potential conflict of interest and therefore did not feel it had to be reported.
He recently announced Hayes will no longer have a policy role in his office.