The flight, carrying 180 passengers including two infants onboard, was on its way to Dibrugarh from New Delhi when it was diverted to Kolkata's Netaji Subhas Chandra Bose International Airport.
"One of the aircraft engines was shut midway which forced the IndiGo Delhi-Dibrugarh flight to made emergency landing at Kolkata airport. It is a very serious issue. The DGCA has launched its investigation into the incident," sources said today.
A response from IndiGo on the issue is awaited.
However, IndiGo had yesterday claimed that its pilot had not sought emergency landing of its flight and Kolkata ATC had acted on its own.
"Despite that cockpit crew did not declare any emergency, ATC (Kolkata) declared full emergency on its own. The aircraft landed safely," IndiGo said in the statement.