Aviation regulator DGCA has issued a show cause notice to IndiGo Airlines over an incident in which the airline did not let a special needs child and his parents board a flight.

The Directorate General of Civil Aviation, has in its investigation report of the incident at Ranchi airport stated that IndiGo handled the passengers "inappropriately".

"The findings of the committee prima facie indicate inappropriate handling of passengers by the IndiGo staff thereby resulting in certain non-conformances with the applicable regulations," said the DGCA, citing the investigation report.

"In view of this, it has been decided to issue a show cause notice to the concerned airline… After hearing their submissions, appropriate action as per law would be taken," the DGCA said.

The airline has been given 10 days to furnish its explanation.

Indigo has responded, saying, "We have received the communication from DGCA on the matter and will respond in due course".

An IndiGo manager had refused to allow the child and his family to board the flight, claiming the boy was in a "state of panic and posed a threat to other passengers.”

He had refused to listen to the appeals of other passengers and two doctors, who were boarding the  same flight, to allow the child to travel.

In a statement, the airline stressed that it takes pride in being "inclusive", playing down suggestions of discriminatory behaviour.

An account of the incident shared on Facebook by a passenger had triggered a huge controversy over the issue.

IndiGo CEO Ronojoy Duttahad supported the decision of the airline’s airport manager to not allow the boy to board the plane.

However, Civil Aviation Minister Jyotiraditya Scindia tweeted: "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".