The Minnesota DFL on Monday referred an internal report on a domestic abuse claim against Keith Ellison to local authorities for further investigation, after an attorney hired by the party found the claim could not be substantiated.

The decision promises to keep alive lingering allegations against the DFL candidate for attorney general, who has denied that he tried to drag a former girlfriend, Karen Monahan, off a bed during a fight in 2016.

"For the purpose of objectivity and getting all of the facts regarding these allegations, we have decided to forward the information in the investigation to local authorities in order to let them review the contents and determine whether further investigation is warranted," read a statement released Monday afternoon by Ken Martin, the chairman of the DFL.

The party declined to release the report produced by Susan Ellingstad, a Minneapolis attorney it hired to conduct the investigation. Martin through a party spokesman declined a follow-up interview request, and Ellingstad did not return a call seeking comment.

Minneapolis City Attorney Susan Segal said she received an e-mail late Monday afternoon from the firm tasked with carrying out the investigation. Because Ellison's son, Jeremiah Ellison, is a Minneapolis City Council member, Segal said she would not be reviewing any materials provided.

"I will be in communication to find a different prosecutor's office to forward the e-mail and attachment for a response, whatever that may be," Segal wrote in an e-mail.

In a statement Monday, Ellison described the probe as a "thorough, independent and fair review" and sought to pivot back to discussing "the issues of this important election." The allegations have loomed over Ellison since they surfaced in August, days before the state's primary.

"Addressing this allegation has been especially challenging given the important national moment we are in," Ellison said. "I believe women who come forward must be heard, and to have their allegations fully investigated. This is why I have complied with this investigation fully, and will do so with any other inquiries. I thank the Minnesota DFL for taking this issue seriously and requesting this investigation."

His Republican opponent, Doug Wardlow, challenged the report's credibility.

"The sham 'investigation' led by the DFL party attorney's legal partner has concluded in favor of the party's Attorney General candidate," Wardlow said in a statement.

In the report, a copy of which was obtained by the Associated Press, Ellingstad wrote Monahan was not willing to release a video she says she has of the incident. She also wrote that Monahan gave multiple explanations for why she would not release the video.

Ellingstad interviewed both Monahan and Ellison, spoke with friends and colleagues of the two and reviewed documents including text and social media messages provided by both Ellison and Monahan. She also interviewed Ellison's ex-wife, Kim Ellison, who "firmly stated" that Ellison did not abuse her "before, during or after" their 25-year marriage.

The attorney, in her report, described Monahan as "unwavering in her claim that the alleged physical altercation occurred" and found credibility both in Monahan's specificity and from accounts from several friends who reported being told about the incident months after it allegedly happened. Ellison meanwhile was "credible in his denial" and "truly seemed not to recall the incident ever happening," Ellingstad wrote.

In the end, Ellingstad wrote, Monahan's refusal to allow a private review of the video prevented a definitive finding.

"An allegation standing alone is not necessarily sufficient to conclude that conduct occurred, particularly where the accusing party declines to produce supporting evidence that she herself asserts exists," Ellingstad wrote. "She has thus repeatedly placed the existence of the video front and center to her allegations, but then has refused to disclose it."

Andrew Parker, an attorney for Monahan, indicated in an interview Monday that there may be circumstances under which Monahan would be willing to share the video as part of an investigation, but did not elaborate. He also pointed to "separate corroboration" of the abuse allegations in the form of Monahan's report to a doctor last year and her son's statement in August that he watched the alleged video.

Ellison has maintained that no such video of abuse could exist "because I never behaved in this way, and any characterization otherwise is false."

Parker said he and Monahan were not provided with a copy of the DFL report. On Twitter Monday, Monahan wrote of her reluctance to release the video: "You are not entitled to my pain and trauma. You are not entitled to see me getting dragged, when my body is being exposed in more ways than one. This is my trauma, I dealt with the abuse. I have already shared more than I was originally comfortable with."

Last week, Ellison requested a U.S. House Ethics Committee investigation into Monahan's allegation, saying he is eager to resolve the matter.

Stephen Montemayor • 612-673-1755