Four contractors have been held responsible for deficiencies detected in the construction of the Delhi-Mumbai Expressway and strict action will be taken against them, Union Minister Nitin Gadkari said on Thursday.

After taking note of the matter, experts from IIT Kharagpur and Gandhinagar inspected the expressway and found deficiencies in its construction.

"We have issued notices to four contractors and will blacklist them. Strict action will be taken. Action will also be taken against concerned officials," the transport minister said during Question Hour in the Lok Sabha.

"After noting deficiencies, we had roped in experts from IIT Kharagpur and IIT Gandhinagar. Initial findings of the report show there are deficiencies in the construction," Gadkari said.

He said the Delhi-Mumbai Expressway is the country's longest such road and was constructed in the shortest time.

"The expressway was constructed at a cost of Rs 1 lakh crore. It has reduced the distance between Delhi and Mumbai by 200 km. The travel time between the two cities has now reduced to 12 hours," he said.