A woman passenger on an IndiGo Airlines flight from Mumbai to Delhi was not allowed to get on the plane for being 'inappropriately dressed' .

The woman was reportedly wearing a 'short dress' and had to change into trousers to get on to the next IndiGo flight on Monday, The Indian Express reported. 

According to one passenger, the woman was wearing a 'frock that ended above her knees'. 

She had landed at Mumbai's Chhatrapati Shivaji International Airport on a Qatar Airways flight from Doha and was to take a connecting flight to Delhi.

The woman was a former Indigo employee herself and her sister is reportedly still an employee at the airline. 

IndiGo has said that it has a 'specific dress code' for employees who avail of 'staff leisure travel privileges' and claimed that the Mumbai ground staff was only following protocol. 

Co-passengers claimed that the woman was crying after she was not allowed to board the flight. 

"While I was waiting for my connecting flight, I heard a commotion and found her (the woman passenger) crying. There were three IndiGo employees who had refused to let her board her flight. They said she was not wearing appropriate clothes," a passenger told The Indian Express

The IndiGo staff even reportedly threatened to deboard other passengers who tried to intervene, according to the report. The airline claimed it was only adhering to its dress code policy. 

"We regret that an IndiGo passenger (who happens to be an ex IndiGo employee and a family member of a current employee) experienced an untoward behaviour at the Mumbai airport... As per the guidelines outlined, employees and the nominated family members are required to maintain a specific dress code, as and when they fly with the airline under the staff leisure travel privileges. Keeping in mind this policy, the Mumbai ground staff followed the protocol to brief this passenger on the dress code policy," its statement to the newspaper said. 

IndiGo is said to have the highest number of passengers among airlines in India, and its current initial public offering (IPO) is expected to take the market value of its owner InterGlobe Aviation Ltd higher than that of Jet Airways (India) Ltd and SpiceJet Ltd, according to Reuters.