Police officials had previously confirmed they were investigating Mills, who represents an area between Orlando and Daytona Beach, in connection with an assault that was reported about 1:15 p.m. Wednesday in the 1300 block of Maryland Avenue SW. They declined to provide further information, citing the “active criminal investigation.”

Police also said their internal affairs bureau would investigate how the call was handled. Two officials familiar with the matter said that was meant to determine why the incident was first characterized as a family disturbance and why the congressman was not taken into custody, given the initial allegations and the woman’s apparent injuries.

Details of the encounter remain murky, and in text messages to The Washington Post, the woman listed on a police report as the victim, 27-year-old Sarah Raviani, denied that an assault occurred. The Post generally does not identify alleged victims of crimes without their consent, but Raviani said in a text message that she was willing to be named.

Mills’s office said in a statement: “This week, law enforcement was asked to resolve a private matter at Rep. Mills’ residence. Rep. Mills vehemently denies any wrongdoing whatsoever, and is confident any investigation will clear this matter quickly.”

Police did not describe how Mills and Raviani know each other, and she did not respond to questions on that issue.

Mills, 44, is an Army veteran who works with humanitarian organizations and has participated in several operations to rescue Americans trapped in war zones in Afghanistan, Haiti and Israel. He serves on the committees on Armed Services and Foreign Affairs.

Two D.C. police officials said Raviani initially told a 911 operator and police she had been assaulted. She also had what seemed to be visible injuries, which ordinarily requires responding officers to arrest the alleged assailant, the officials said. Raviani also told police her phone was broken during the encounter, the officials said. The officers did not arrest Mills at his apartment Wednesday, and a supervisor classified the offense internally as a family disturbance, the officials said. Police commanders later learned of the incident, reviewed the reports and body-camera footage from the responding officers, and reclassified the case as a domestic violence assault, the officials said.

A police report contains no details of the alleged assault, but does identify Raviani as the victim. The D.C. Office of Unified Communications, which runs the 911 emergency dispatch center, denied a request under the Freedom of Information Act to provide a transcript or audio recording of the woman’s 911 call.

Contacted by a Post reporter via text Thursday evening, Raviani said she “reached out to police for a personal matter.” She said she had been tired from a 14-hour flight “and had been drinking both during my flight and when the officers arrived.”

“I was already feeling emotional, and that definitely didn’t help,” Raviani said. “When [police] got there, they noticed some marks and bruises on my arms, which I explained were from eczema and some activities during my trip to Dubai.” She said “there was absolutely no physical altercation. Unfortunately, things have since been taken way out of context.” She also denied that her phone was broken during an encounter with Mills.

Raviani said she felt people alleging she was assaulted are using her case “for political purposes,” though she did not explain further. Reached on Friday, after police had sent a warrant application to the U.S. attorney’s office for review, Raviani said, “I stand by what I stated yesterday, that there was no physical assault.”

Police can seek to arrest Mills without approval from the U.S. attorney’s office, but prosecutors still must decide whether the evidence is strong enough to move forward with a criminal case. Seeking approval in advance for an arrest is typically done so that prosecutors and police agree that there is sufficient evidence, and the matter is not dropped quickly after police make an arrest.

A spokesman for interim U.S. Attorney Ed Martin declined to comment.

At a news conference Friday, D.C. Mayor Muriel E. Bowser (D) declined to comment on the report or the investigation into the congressman’s conduct, but confirmed that D.C. police had launched an internal investigation. “I don’t know anything about a report being changed, so I can’t say anything about that,” Bowser said. “I can confirm that there is an internal investigation on making sure that all of our members did what they were supposed to do according to MPD policy.”

Jenny Gathright contributed to this report.