The blaze erupted between 12.45 am and 1:00 am in the first floor of the cargo terminal, located near the Air Traffic Control (ATC) building, which houses offices of around 20 international airlines, including Air India, Air Sri Lanka and others.
Initially, airport sources said the maintenance staff tried to douse the flames with the fire fighting arrangements at the cargo complex but failed to contain the fire.
The fire brigade was informed at around 1.15 am only, police and fire brigade officials said.
"There is no damage to cargo. No cargo has been lost. No one was injured," a spokesperson for Delhi International Airport Ltd (DIAL), which operates the IGI Airport, said.
Thirty-three fire tenders were rushed to spot which doused the fire in five hours at around 6.30 am.
The first floor of the cargo building that houses the offices of around 20 airlines and the HR department of Celebi, the ground handling services company that manages cargo operations at IGI Airport, was completely gutted.
"The fire broke out in the import section of the cargo. There are three buildings housing the import section and the fire broke out in the second building. All the offices have been gutted. There was no one in the office as it was night hours," the officials said.
The cause of fire is yet to be ascertained though a short circuit is suspected to be the cause of the blaze.