A Hyderabad-bound Indigo flight received a bomb threat at the Indira Gandhi International airport on Sunday night, forcing authorities to ground the aircraft and evacuate the passengers.
Officials said the cleaning up of the plane is going on and it is not yet verified whether it was a hoax call.
Anti-sabotage checks are also being carried out on the aircraft 6E 307.
It is suspected that the call was made in a bid to delay the flight by a few hours, a Central Industrial Security Force official said.
The 164 passengers on board the plane, including five crewmembers, were safely evacuated and the aircraft was moved to the isolation bay.
Meanwhile, a man, identified as 20-year-old Mubarak, has been arrested from Bhagirath Vihar area in East Delhi in this connection, said Deputy Commissioner of Police (IGI, airport) K C Trivedi.
Mubarak is the relative of one of the three passengers, identified as Ruzwan Malik, who reported late for the flight, a CISF official said.
The arrest came after the CISF personnel provided the Delhi police with the number of the PCO in Yamuna Vihar from which Mubarak had allegedly called the Indigo call centre, claiming there were explosives and weapons on board the plane.
An Indigo spokesperson said, "Our call centre received a threat and we instantly acted and grounded the flight. All passengers are safe."
