The DFL Party's attempt to find a law enforcement agency willing to investigate a domestic abuse claim against U.S. Rep. Keith Ellison was mired in uncertainty Wednesday, after the Minneapolis Police Department said it would seek to refer the case to another jurisdiction.

Earlier Wednesday, the DFL asked Minneapolis police to investigate after both a city attorney and a county prosecutor declined to review a report the party commissioned that did not substantiate the allegation.

Ellison's former girlfriend, Karen Monahan, alleges that the Democratic candidate for attorney general tried to drag her off a bed during a fight in August 2016. He denies it.

"Due to a conflict of interest, or the appearance of a conflict of interest, the Minneapolis Police Department will not be handling the matter involving Congressman Keith Ellison," read a police statement. It said the department is in communication with other law enforcement agencies to which it may refer the case. Ellison's son, Jeremiah Ellison, is a member of the Minneapolis City Council.

Charlene Briner, a senior adviser for the DFL, had told the Star Tribune that the party sent its investigative report to the Minneapolis Police Department and requested it "investigate the claims described in the report to determine whether any criminal conduct occurred."

Susan Ellingstad, the attorney who wrote the 15-page report, found merit in both Monahan's and Ellison's statements, but concluded that the claim could not be substantiated because Monahan refused to provide a video of the incident that she says she has.

Minneapolis City Attorney Susan Segal, who received the report Monday from the DFL, forwarded it to Dakota County Attorney James Backstrom to avoid her own conflict of interest given Jeremiah Ellison's position. But in a letter to Segal on Tuesday, Backstrom wrote that his office would not "review any investigation completed by the law firm retained by the Minnesota DFL Party or any other private investigator without the completion of an investigation by a law enforcement agency."

In a statement earlier this week, Ellison said that he had "complied with this investigation fully, and will do so with any other inquiries." Ellison has also requested a U.S. House Ethics Committee investigation into Monahan's allegation.

Andrew Parker, an attorney representing Monahan, said Tuesday that Monahan would "welcome any investigation that is fair and impartial." He would not comment on whether Monahan would file a complaint alleging criminal activity.

Stephen Montemayor • 612-673-1755 Twitter: @smontemayor