The Japanese start-up ALI Technologies, which had hoped to reimagine urban transport with a futuristic hoverbike, has filed for bankruptcy.

Its US parent company said the move was part of a planned relocation to California, where it hopes to revive its dreams with a new business partner.

ALI Technologies' hoverbike was heavily publicised - with Prince Albert II of Monaco pictured atop the craft at one point.

But it never sold in big numbers.

The bike, which executives once said was inspired by Star Wars, resembled a kind of aerial water scooter.

It could fly for about 40 minutes at up to 100km/h (62mph) on a single charge.

Chief executive Daisuke Katano said he hoped it would provide nothing less than a "new method of movement".