"The Centre is saying old diesel vehicles are not causing pollution, (while) Delhi government is saying vehicles from outside are also not causing pollution. Something must be wrong somewhere," a bench headed by NGT Chairperson Justice Swatanter Kumar said.
The Tribunal's observation came after the Delhi government's counsel informed that only 41 of 759 vehicles entering Delhi were found to be violating pollution norms.
The NGT has constituted three teams with officials from transport enforcement, Central Pollution Control Board and Delhi Police to check vehicles entering Delhi at different entry points.
On the issue of construction of Eastern and Western Peripheral Expressway, the NGT pulled up Haryana government for moving at "snail's pace" in awarding the work.
"You had given an undertaking to the Supreme Court that both Expressways would be completed by 2017. Why have you not alloted work till date," the bench asked.
Irked at the "lackadaisical" attitude of the Haryana government, the green panel summoned its top officers and those of National Highways Authority of India and Haryana State Industrial Development Corporation to appear on July 22.
During the hearing, Additional Solicitor General Pinky Anand, appearing for Ministry of Road Transport and Highways, said that most countries adopt fitness tests, including emission checks, of vehicle as a criterion for curbing pollution and not the age of the vehicle.