A young Israeli entrepreneur has come up with a piece of hand luggage that can be converted into a larger, hold-only bag at the touch of a button.

At its smallest size, the Fugu case - still in prototype stage - complies with airline limitations on cabin bags.

However, a button activates an air-pressure mechanism that inflates its side walls and expands the case to the maximum-sized bag allowed in the hold.

The flexible bag gives air passengers the option of paying less to transport their luggage if they decide to reduce the amount they carry on either an outbound or inbound flight.

Daniel Gindis, vice president of Business Development at Fugu Luggage, said: "Imagine the amount of money you could save with this bag."

The company is still raising the funds to bring the case to market next year, and hopes to sell it for around £190.