In an unusual incident, an Air India flight which had taken off from Delhi airport early on Thursday returned back after the pilot reported presence of bat to Air Traffic Control (ATC).

Air India flight to Newark (EWR) left Delhi's IGI Airport at 2:20 am as scheduled. The bat was spotted after the plane was in the air for about 30 minutes. The flight captain decided to take the plane back to the original base (Delhi).

"AI-105 DEL-EWR returned back to base (Delhi) after departure due to this local standby emergency was declared. On arrival, it was learnt that a bat was seen inside the cabin by crew members. Wildlife staff were called to catch and remove the bat from cabin. The aircraft landed safely at around 3:55 am. Later flight was declared Aircraft on Grounded (AoG)," Air India officials told ANI.

DGCA officials said fumigation was carried out and bat carcass was retrieved from the aircraft.

"Air India B777-300ER aircraft VT-ALM operating Flight AI - 105 (Delhi- Newark) was involved in air-turn-back due to bat reported in the cabin by cabin crew after departure. Fuel was jettisoned and the aircraft landed safely at Delhi. After landing fumigation was carried out and a dead bat carcass was retrieved from seat 8DEF area," a senior DGCA official told ANI.

He said the bat was found dead inside the plane in the business class area.

The incident was reported to the airline's flight safety department for a detailed investigation.

Sources said the airline has asked the engineering team for a detailed report on the incident.

The Air India engineering team submitted its initial report to flight safety and stated that unwanted mammals came from third parties.

"The probable reason/cause may be loading vehicles like those for catering because all the time rats/bats come from their vehicle only," an Air India official told ANI.

The passengers were shifted to another plane and Air India flight AI-105 landed in Newark at 11:35 am local time.