Lawyers representing Dr David Dao say a condition of the payout is that the “amount remain confidential”.

Upon confirming the settlement Dao’s lawyers said United chief executive Oscar Munoz promised “he was going to do the right thing and he has," BBC News reports.

Dao was forcibly removed from a Chicago-Louisville service earlier this month by airline law enforcement officers after refusing to give up his seat to accommodate United staff on the aircraft.

Video footage of the Vietnamese-American physician’s treatment sparked widespread criticism of United after it was posted online and viewed by millions of people.

Dao suffered concussion, a broken nose, and lost two front teeth during the incident – with his lawyer telling journalists Dao found the experience "more horrifying and harrowing" than fleeing the Vietnam War.

Thomas Demetrio, representing Dao, said his client "has become the unintended champion for the adoption of changes which will certainly help improve the lives of literally millions of travellers".

The settlement came the day after United announced a number of policy changes to its customer service procedures which boss Munoz branded as a “turning point” for the carrier.

He added that the changes, along with a separate enquiry being carried out into the incident, marked a “culture shift toward becoming a better, more customer-focused airline”.

Among the policy changes was the pledge from United to offer passengers up to $10,000 (£7,800) to give up seats on overbooked flights.