The ruins of the ancient building were found on top of a mound covered with grass and trees along the Jammu-Rajouri national highway, he said.
The spokesman said Deputy Commissioner Rajouri Shahid Iqbal Choudhary along with Senior Superintendent of Police Yougal Manhas and other senior officers visited the spot.
They inspected the ruins of the ancient fort where the remnants of walls, courtyard and barracks can be vividly seen, the spokesman said.
"Preliminary survey found the ancient structure spread over an area of 2 Kanals (0.25 acres). However, the exact details of the site will be assessed only after scientific excavation of the site," the spokesman said.
He said the architecture of the fort is similar to the Rajouri Fort and the ancient Sarais along the Mughal Road.
The time of the existence of the fort could not be ascertained immediately and the matter is being taken up with the Archaeology Department for taking over this ancient site and initiating measures for its preservation and protection, he said.