The accident came to light when a vehicle driver informed the nearest checkpost about the body of the leopard lying on the road near Kuriyani forest nursery at around 2 AM on Saturday night.
The accident spot is in close proximity of Kishanpur Wildlife Sanctuary of Dudhwa Tiger Reserve.
South Kheri divisional forest officer (DFO) Neeraj Kumar, Dudhwa deputy director Vinod Krishna Singh, Kishanpur range officer Kalpnath Gautam and other officers rushed to the spot.
"The injuries on the body and circumstances indicate that the leopard have been hit by a mini van-like vehicle," he said.
"Details of the vehicles which passed through the way on Saturday night are being examined and further action will be taken after the identification of the vehicle," he added.
The DFO described the leopard as fully grown up, male, probably 3-4-years-old with all parts of the body intact.