Scientists working for the US military have developed brain implants that could control sharks remotely and use them as spies.

A team from Boston University has developed electrodes that can be implanted in dogfish, which are genetically very similar to sharks, and use them to control the shark's responses.

The electrodes simulate smells in the water and can be used to guide the animal around its tank using a wireless laptop.

Project engineer Walter Gomes, of the Naval Undersea Warfare Centre in Rhode Island, told New Scientist that the next step will be to implant the device into blue sharks and release them into the ocean off the coast of Florida.

Gomes explained that, while wireless signals would not work underwater, the group had developed a way to control the signals sent via sonar, and could control movement from a distance of 300 miles.

Sharks would be very useful as spies, according to the Naval Undersea Warfare Centre, since they are virtually silent in the water, can sense smells from great distances and can track the electrical signals emitted by a human target.