A passenger who was dragged from a United Airlines plane after refusing to disembark attempted to hit a security agent, an internal document sent by the company reportedly claims.

A log of the incident available to staff and obtained by Mail Online appears to show the airline claim that 69-year-old grandfather David Dao “attempted to strike law enforcement”.

The note, apparently written at Chicago's O'Hare Airport, where the flight was due to depart from, was printed using United’s internal reporting system.

Video footage of the incident sparked outrage around the world, with many people threatening to boycott the airline.

The accusations said to have been made by United come after a leaked email to airline employees revealed Dr Dao was removed so staff could take his seat.

United Airlines was contacted for comment by The Independent but had not responded at the time this article was published.

On Monday, United Airlines’ CEO Oscar Munoz released a statement describing the incident as an “upsetting event”.

“I apologise for having to re-accommodate these customers,” he said.

The passenger was dragged off a United flight after refusing to leave (Jayse D Anspach)

“Our team is moving with a sense of urgency to work with the authorities and conduct our own detailed review of what happened.

“We are also reaching out to this passenger to talk directly to him and further address and resolve this situation.”

The incident took place on the United flight 3411 on 9 April from Chicago to Louisville.

The man in question was selected but refused to leave, claiming he was a doctor who needed to get to work to see patients the next day.