New York: Spotting concealed contraband at ports can now be a lot easier as researchers at the Massachusetts Institute of Technology (MIT), including an Indian-origin scientist, have developed an oval-shaped submersible robot that can perform ultrasound scans.

The robot is a little smaller than a football with a flattened panel on one side that it can slide along an underwater surface.

Sampriti Bhattacharyya, a graduate student in mechanical engineering, designed the robot together with her advisor professor Harry Asada.

Originally designed to look for cracks in nuclear reactors' water tanks, the robot could also inspect ships for the false hulls and propeller shafts that smugglers frequently use to hide contraband.

Because of its small size and unique propulsion mechanism - which leaves no visible wake - the robots could, in theory, be concealed in clumps of algae or other camouflage.

Fleets of them could take care off ships at the port without alerting smugglers and giving them the chance to jettison their cargo.

"It is very expensive for port security to use traditional robots for every small boat coming into the port," Bhattacharyya said.

Half of the robot - the half with the flattened panel - is waterproof and houses the electronics.

The rechargeable lithium batteries used in the prototype, Bhattacharyya noted, last about 40 minutes.

Their next prototype, Bhattacharyya said, will feature wirelessly rechargeable batteries.