One of the police officers who forcibly removed a United Airlines customer in an incident that became a public relations disaster for the carrier said “minimal but necessary force” was used after the passenger acted aggressively, according to an incident report.

Video recorded by other passengers showed David Dao, a 69-year-old doctor, being dragged down the aisle with blood on his face after refusing to give up his seat on a flight from Chicago to Louisville, Kentucky on April 9.

Dao suffered a concussion, a broken nose and lost two front teeth and is likely to sue the airline, according to his lawyer, Thomas Demetrio. Initially, United did not apologize to Dao and described him as “disruptive and belligerent.” Some social media users in the United States, Vietnam and China called for a boycott.

In the incident report, which was released by city authorities on Monday and posted online by the Chicago Tribune, aviation police officer Mauricio Rodriguez said Dao became combative after he and two other officers tried to persuade the doctor to leave the plane.

According to the incident report, Dao told the officers: “I’m not leaving this flight that I paid money for. I don’t care if I get arrested.”

An officer identified in the report as James Long then tried to get Dao out of his seat, at which point the passenger “started swinging his arms up and down fast and violently,” Rodriguez said in the report.

Long lost control of Dao as he swung, causing Dao to fall and hit his mouth on the arm rest. Long then “assisted the subject by using minimal but necessary force” to get him off the aircraft, the report quoted Rodriguez as saying.

A spokesman for Demetrio told the Wall Street Journal that the police version of events outlined in the report was “utter nonsense. Consider the source.”

Chicago’s aviation department on Monday told the Journal that the three officers involved remained on leave and that it was conducting an investigation.

United said on Friday it had asked a U.S. Senate panel for an extra week to answer questions about the incident. The carrier’s chief executive officer, Oscar Munoz, wrote that he was “personally committed to putting proof behind our promise” in the carrier’s commitment to reforms.

-REUTERS