The passenger who was dragged from an United Airlines flight is 69-year-old grandfather Dr David Dao.

Footage of the Vietnamese-American being hauled off the overbooked flight at Chicago's O'Hare International Airport on Sunday caused outrage on Monday.

Dr Dao was heard in videos captured of his shocking eviction saying he needed to get home to Louisville so he could see patients.

DailyMail.com can reveal Dr Dao is a father of five and a grandfather, who specializes in internal medicine. Four of his five children are doctors.

His wife Teresa, 69, is a pediatrican who trained at Ho Chi Minh University in Saigon and also practices in Elizabethtown, Kentucky - about 40 miles south of Louisville.

Their eldest son Tim, 34, practices medicine in Texas; their second son Ben, 31, is a medical graduate; their daughter Christine, 33, is a doctor in Durham, NC; and their youngster daughter Angela, 27, is a medical graduate of the University of Kentucky.

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Dr David Dao has been revealed as the man who was dragged from a United flight in Chicago on Sunday. He is pictured with his wife, Teresa, and one of their grandchildren

Beaten and bloodied: Dr Dao is pictured bleeding from the mouth after he was body slammed by cops and dragged off the overbooked United flight at Chicago O'Hare

Dr David Dao and Teresa Dao are pictured with four of their grandchildren during a holidays celebration in 2015

Their other daughter, Crystal – Christine’s twin – is a married mother in Barrington, Illinois.

Dr Dao has previously worked at Hardin Memorial Hospital and owned a medical practice.

It was also revealed he had previously been given a suspended jail sentence for illegally obtaining and trafficking controlled substances by fraud and deceit.

Dr Dao is also a keen poker player, and has competed in World Series of Poker events in the past - winning a total of $234,664

His license was suspended in 2003, and it was then partially re-instated in 2015.

Dr Dao is also a keen poker player, and has competed in World Series of Poker events in the past.

He joined the circuit in 2006, and had his best result when he finished second in a tournament in 2009.

The WSOP's website claims he has pocketed $234,664 in winnings over his time on the felt.

In the hours after his identity was revealed, United saw its stock price crash in morning trading action.

The airline's share price hit a low of $68.39 at 11.13am, after opening the day at $70.15. It was a drop of about 2.6 per cent.

But the price has recovered during the early afternoon, and is none back at $69.82, MarketWatch reports.

It came after United CEO Oscar Munoz released a statement Monday night that doubled down on his airline crew's decision to remove an elderly passenger, claiming he was 'disruptive and belligerent'.

The airline is facing a furious backlash after footage emerged of the 69-year-old, bleeding heavily as he was pulled from the jet.

Amidst the anger, Munoz issued a public apology saying he 'apologized for having to re-accommodate these customers.'

But in a private email to employees, the CEO defended the crew's actions, calling the passenger 'disruptive and belligerent' and praising his staff for going 'above and beyond'.

United Airlines' CEO Oscar Munoz (pictured in June 2016) has come under fire for his response to the scandal

United CEO Oscar Munoz has doubled down on his airline crew's decision to remove an elderly passenger, claiming he was 'disruptive and belligerent'

Screaming: The man who had refused to to give up his seat on the overbooked United flight from Chicago to Louisville on Sunday night was dragged off the plane by three cops

Social media erupted immediately, labeling Munoz and United 'tone deaf' and 'condescending'.

Munoz said that while he was 'upset' to hear about the man being violently dragged off the flight, that airline crew had simply been following 'established procedures.'

The CEO described how flight crews had offered up to $1,000 in compensation for anyone willing to catch the next flight before approaching the passenger to 'explain apologetically' that he was being denied boarding.

He had then 'raised his voice and refused to comply' with the crew's requests to leave the aircraft, and became increasingly 'disruptive and belligerent,' he said.

'Our agents were left with no choice, but to call Chicago Aviation Security Officers to assist in removing the customer from the flight, he repeatedly decline to leave.'

Munoz added that the passenger refused to comply with the officers who then 'physically removed him from the flight as he continued to resist – running back onto the aircraft in defiance of both out crew and security officials.'

The comments have sparked outrage online with people claiming that the CEO was attempting to shift blame to the police

'While I deeply regret this situation arose, I also emphatically stand behind all of you, and I want to commend you for continuing to go above and beyond to ensure we fly right,' he said.

The CEO did, however, concede that there were 'lessons we can learn' from the experience and that United will continue to look into the incident.

He also had a final reminder that treating customers with 'respect and dignity' should be matter of course, 'no matter how challenging the situation.'

The comments have sparked outrage online with people claiming that the CEO was attempting to shift blame to the police.

Others said that 'lousy protocol' was never an excuse for a 69-year-old man beating left bloodied by security.

'Beating and bloodying a 69 year-old doctor is "protocol" @United ?' one Twitter user asked.

Distressing: Children were crying in distress as the three officers manhandled the man out of his seat. Passengers had been offered $800 to take a flight the next day but none volunteered

Another said that Munoz was 'trying to shift blame to police/aviation security (not United employees). The public doesn't make a distinction.'

Nicholas Kristof added: 'In any big company, staff will sometimes do stupid things. At United, the CEO then endorses the stupidity and claims it as company policy!'

Others pointed out that the customer had also appeared to have followed 'protocol' right up until he was dragged off the plane.

HOW DOES UNITED DECIDE WHO GETS BUMPED FROM OVERBOOKED FLIGHTS? United's contract of carriage states that passengers to be forcibly taken off a flight in the event of overbooking will be 'determined based on a passenger’s fare class, itinerary, status of frequent flyer program membership, and the time in which the passenger presents him/herself for check-in without advanced seat assignment.' That means that if you have a certain type of fare class, checked in early, have a flier status such as gold, or even just own a barely used frequent flier card, you are less likely to be bumped. But passengers taking advantage of budget seats appear to be of less value to the airline. Advertisement

'#United Pay for your ticket, sit down, get attacked, bloodied and humiliated. And the CEO is now saying the person deserved it. #SHAME,' one Twitter user wrote.

'No accountability for lousy protocol,' another added. 'It will be a cold day in Hades before I allow these lackwits to fly me anywhere.#BoycottUnitedAirlines.'

An airport cop who allegedly body-slammed the passenger was put on leave today - as his bosses condemned his actions amid mounting outrage over video of the incident.

The Chicago Department of Aviation said it 'obviously' did not condone the behavior of the security officer who was filmed slamming the man into an arm rest, knocking him unconscious and dragging him away by his arms as he bled from the mouth at O'Hare.

Another clip shows the dazed man chants 'just kill me, just kill me' as blood pours from his mouth.

In his public apology, Munoz said today: 'This is an upsetting event to all of us here at United. I apologize for having to re-accommodate these customers.

'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 aviation department released a statement to the Chicago Sun-Times, which read: 'The incident on United flight 3411 was not in accordance with our standard operating procedure and the actions of the aviation security officer are obviously not condoned by the Department.

Unhinged: The man claimed to be a doctor and screamed wildly and he was manhandled by the cops

'That officer has been placed on leave effective today pending a thorough review of the situation.'

One passenger also told the Washington Post the man claimed as he was being dragged off the plane he was chosen because of his ethnicity.

'He said, more or less, 'I'm being selected because I’m Chinese",' the passenger told the Post.

The same passenger went on to tell the newspaper a United official walked onto the plane during the incident and said the plane would not be taking off until four passengers disembarked so the employees could fit on.

He said the official announced: 'We have United employees that need to fly to Louisville tonight. … This flight’s not leaving until four people get off.'

'That rubbed some people the wrong way,' Tyler Bridges said, recounting the comment.