United Airlines has a reached a settlement for an undisclosed sum with the passenger who was dragged from a Chicago flight earlier this month.

Dr David Dao, a 69-year-old Vietnamese-American doctor, was taken to hospital after Chicago aviation police dragged him from the plane to make space for four crew members on the flight from the city's O'Hare International Airport to Louisville, Kentucky.

"I hope he becomes a poster child for all of us, someone’s got to," Thomas Demetri, Dr Dao's attorney, said during a press conference on Thursday. "Are we just going to continue to be treated like cattle?"

Mr Demetrio said that Dr Dao had suffered from a concussion after the United Airlines event as well as a broken nose and two missing teeth. He said that his client would need to get reconstructive surgery for damaged sinuses.

The settlement includes a provision that releases Republic Airways, which was contracted to operate the flight for United, and the Chicago Police from all responsibility in the incident.

Dr Dao was removed from the flight after crew members asked passengers to volunteer to be transferred onto a later flight. Dr Dao was then chosen by the airline to be switched to a later flight after attempts to convince passengers to voluntarily leave the plane failed. When Dr Dao insisted on staying on the plane, police forcibly removed him.

A video of his removal, which was taken by a fellow passenger and later went viral, showed police violently pull him out of his seat. Dr Dao then flopped into the aisle and remained mostly still as the police dragged him toward the front of the plane. A second video showed Dr Dao reenter the aircraft with blood flowing down his face, quietly saying, "I want to go home, I want to go home."