Doctor dragged off United flight was felon

• Dr David Dao's troubled medical past is revealed in court documents
• His wife Teresa - also a doctor - reported him to medical authorities and his secret inappropriate gay relationship with a patient was revealed
• Father of five, 69, was convicted of a felony - but avoided prison time  - because he was giving the man prescription drugs in return for gay sex
• He denied the gay sex even though he was caught on camera shirtless and in his pants with Brian Case, his lover, 26, who was a fellow worshiper at his church
• Case said he believed that Dao wanted to hook him on prescription narcotics including Oxycontin so he would keep coming to him for gay sex 
• Psychiatrist found Vietnamese-born doctor had series of issues and one doctor wrote that he 'he would unilaterally chose to do his own thing'
• He only got his licence back after agreeing to be drug tested and polygraphed
• United are facing a furious backlash and boycott calls over the video; their stock price plunged as Wall Street reacted to passenger fury
• DailyMail.com also reveals that the airline told staff he had 'tried to strike law enforcement' - despite no evidence for that on the video 

The troubled past of the doctor who was dragged off United Airlines in an incident which has plunged the company into crisis is revealed in official documents - including his felony drugs conviction and need for 'anger management'.

Dr David Dao had a past of illicit gay sex with a patient in return for giving , and tested positive for drugs, official documents reveal.

The medic, who specializes in lung disorders, was accused of refusing to give up his seat on Sunday's United Express flight UA3411 flight from Chicago to Louisville for the airline's staff.

Cellphone footage of the Vietnamese-born grandfather's ejection has caused an uproar with critics claiming officers were heavy-handed in taking the senior from the flight.

The doctor spoke to WLKY and told them 'everything' was injured. 

Dr Dao has not yet sued the airline but it is clear that if he did, the documents would be likely to be used by United in their attempt to defend their actions. 

The row over its handling deepened on Tuesday as DailyMail.com revealed how United told its staff that the doctor 'tried to strike law enforcement'. That version of events is not apparently supported by videos taken by other passengers.

The disclosure of what they said to their own staff came after United's CEO, Oscar Munoz, was accused of being 'tone-deaf' for his non-apology to the doctor.

United lost $800 million of its value as shared plunged on Wall Street in the wake of the PR disaster.