NEW YORK – Lawyers for the passenger dragged from a United Airlines plane in Chicago have filed an emergency request with an Illinois state court to require the carrier to preserve video recordings and other evidence related to the incident.

Citing the risk of “serious prejudice” to their client, Dr. David Dao, the lawyers want United and the City of Chicago, which runs O’Hare International Airport, to preserve surveillance videos, cockpit voice recordings, passenger and crew lists, and other materials related to United Flight 3411.

The filing with the Cook County Circuit Court likely prefaces an eventual lawsuit against United for the April 9 incident, where Dao was snatched from the seat he had paid for, and was dragged by his hands on his back off the parked plane, which had been bound for Louisville, Kentucky.

United Chief Executive Officer Oscar Munoz on Wednesday issued Dao an apology and said the company would no longer use law enforcement officers to remove passengers from overbooked flights after global outrage erupted over the way Dao had been treated by airline and airport security staff.

Munoz said United would be examining its incentive program for volunteers on overbooked planes.

The Sunday evening incident caused a furore around the world as video recorded by fellow passengers showed airport security officers yanking Dao from his seat aboard the flight.

Much of the uproar stemmed from Dao’s status as a paying passenger who was being removed to make room for additional crew members on the overbooked flight.

The backlash from the incident resonated around the world, with social media users in the United States, China and Vietnam calling for boycotts of the No. 3 US carrier by passenger traffic and an end to the practice of overbooking flights.

As of Tuesday, Dao was still in a Chicago hospital recovering from his injuries.

‘No more police on flights’

As the PR disaster rages unabated, United Airlines CEO Oscar Munoz has announced that the airline will not use law enforcement officers to remove overbooked passengers from aircraft.

Munoz told ABC News the problem resulted from a “system failure” that prevented employees using “common sense” in the situation.

He said he had no plans to resign over the incident that has drawn condemnation around the world.

Munoz profusely apologised to the passenger, his family, passengers and the airline’s customers.

“This can never, will never happen again,” he said.

– RAW