The boxer and reality TV star was travelling with another man from New York to a training camp in Colorado via Dallas Fort-Worth, and alleges they were removed from the flight because his friend's mask 'was not high enough'.
In a video shared to his Twitter, the former light-welterweight world champion said he was 'disgusted' by the treatment he received, although American Airlines has since released a statement clarifying its position.
Khan said: "I was taken off the plane today when I was going to training camp to Colorado Springs by the police.
"Obviously a complaint was made by American Airlines staff, they said that my colleague's mask was not high enough and not up, that they had to stop the plane and take me and my friend off when I did nothing wrong.
"They kicked us both off, I was sat on 1A, he was sat on 1B - I find it so disgusting and so disrespectful. I was supposed to go to Colorado Springs for a training camp and now I'm back in New York for another day."
He continued: "Now I have to reschedule another airplane to travel back to training camp which is really upsetting, for no reason this was and I'm just so disgusted that American Airlines would do this to us and ban me from travelling.
"I'm sure there must be cameras on the airplane that they could see, or someone should see, to see that if my colleague really was bad in anyway or caused a scene in a way where he had to be taken off the plane - I've never seen this happen before."
Khan also added the hashtag #Notallterrorists to his original post.
In its statement, the airline said the aircraft 'returned to the gate' before take-off to 'deplane two customers who reportedly refused to comply with repeated crew member requests to stow luggage, place cell phones in airplane mode and adhere to federal face covering requirements'.
They also said the two passengers had left the plane without any incident, and added that the police were present only as a matter of protocol.
The statement said Khan and his friend had not been banned from travelling again with American Airlines or any of its partners, nor had they been placed on an 'internal refuse list'.
Their customer relations team is also contacting Khan 'to learn more about his experience and reinforce the importance of policies implemented for the safety of our customers and crew'.
The full American Airlines statement reads: "Prior to take-off on Sept. 18, American Airlines Flight 700, with service from Newark Liberty International Airport (EWR) to Dallas-Fort Worth (DFW), returned to the gate to deplane two customers who reportedly refused to comply with repeated crew member requests to stow luggage, place cell phones in airplane mode and adhere to federal face covering requirements.
"Our Customer Relations team has reached out to Mr. Khan to learn more about his experience and reinforce the importance of policies implemented for the safety of our customers and crew."Featured Image Credit: Twitter/Amir Khan