The airline turned away Dr Frederic Schroeder, who had a reserved seat on Saturday's Flight AK887 from Bangkok to Kuala Lumpur, said Monthien Boonton, the president of the association.

 According to Monthien, airline staff told Dr Schroeder that blind passengers travelling alone were not allowed on board because there were no attendants to take care of them. Monthien claimed that many blind passengers had previously travelled alone on Thai AirAsia without any problems.

Dr Schroeder was forced to travel on Malaysia Airlines instead.

Monthien said the incident would affect Thailand's reputation because Dr Schroeder was a well-known person and a high-ranking officer of the US government.

Thai AirAsia's chief executive officer, Tassapon Bijileveld, defended the company's staff and said that it was not discriminatory to prevent disabled people from boarding the airline's planes if they were travelling alone.

"As a low-cost carrier, we have a limited number of flight attendants. Without companions, the disabled need one attendant to lead them to their seat and another to carry their bags. Providing such help would result in poorer service as a whole, as the attendants would be unable to take care of other passengers," Tassapon said in a phone interview.

He added that the airline welcomes the disabled when they have travelling companions.