India's aviation minister has said he is investigating a domestic airline after it allegedly refused to let a disabled teenager board its flight.

The airline's staff told the teenager's parents that he was a risk to other passengers.

The incident sparked widespread outrage with many calling out the airline for discriminatory behaviour.

IndiGo has denied the allegations, saying it prides itself on being an inclusive organisation.

Aviation minister Jyotiraditya Scindia on Monday promised "appropriate action", saying he was personally investigating the incident.

"There is zero tolerance towards such behaviour. No human being should have to go through this," he wrote on Twitter.

The Directorate General of Civil Aviation (DGCA) has also sought a report from the airline.

There is zero tolerance towards such behaviour. No human being should have to go through this! Investigating the matter by myself, post which appropriate action will be taken. https://t.co/GJkeQcQ9iW

— Jyotiraditya M. Scindia (@JM_Scindia) May 9, 2022

The incident, which took place on Saturday at the Ranchi airport, came to light after one of the co-passengers, Manisha Gupta, wrote about it on Facebook.

Ms Gupta said that ahead of the flight, the teenager looked visibly distressed: "By the time he had gone through security check and reached the gate (almost an hour ahead of boarding), he seemed to be in the throes of hunger, thirst, anxiety and confusion."

She added that the parents had managed to placate his meltdown well, "with patience, some cajoling, some stern-ness, many hugs etc" and that, other passengers also stopped by to offer help to the couple.

But when the IndiGo staff saw him, she says they warned the parents that they would not let them board, "if the child did not quieten down and become 'normal'".

"Then we witnessed the full display of brute authority and power. The Indigo staff announced that the child would not be allowed to take the flight. That he was a risk to other passengers. That he would have to become 'normal', before he could be travel-worthy," she wrote.

She added that other passengers on the flight opposed the staff and assured them that they had no objection to the child and his parents boarding the flight.

"A group of doctors, travelling on the same flight, offered to provide full support to the child and his parents if any health episode were to occur mid-air," Ms Gupta wrote.

But the airline held its ground, with its manager - according to Ms Gupta - insisting that the child was "uncontrollable" and "in a state of panic".

Ms Gupta's post has since gone viral, leading to widespread anger and condemnation.

IndiGo in a statement said it took the step for the sake of the safety of its passengers, adding that it made the family comfortable by providing them a hotel stay and that they flew the next morning to their destination.

"We regret the inconvenience caused to the passengers. IndiGo prides itself on being an inclusive organisation, be it for employees or its customers; and over 75,000 specially abled passengers fly with IndiGo every month," it said.

India has more than 26 million people living with physical or learning disabilities, but there is little infrastructure to support them in their everyday life.

Campaigners say disabled people also routinely face stigma, discrimination and harassment.

In 2019, a disability activist and polio survivor was asked to remove her trousers at the Kolkata airport. Two years before that, a female para-athlete was forced to sleep on the floor of a train as she had been allotted an upper berth against the rules.