A lawsuit has been filed against Apple, accusing the technology giant of promising more available storage space than it actually delivers in its iPhones, iPads, and iPod touch devices.

The plaintiffs argue that while Apple advertises 16 gigabytes of digital storage on lower price models of gadgets such as iPhones, about a fifth of that is eaten up by the latest operating software.

The percentage of space touted as available for digital content such as photos, video, or music shrinks further on Apple gadgets built with eight gigabytes of storage, it is claimed.

Apple's latest operating system, iOS 8, which was beset with problems when it launched in September, takes up as much as 23.1% of storage capacity on some devices.

'Forced to pay for storage'

The lawsuit is being brought on behalf of two men from Florida - Paul Orshan and Christopher Endara - in a district court in northern California.

They also complain that once Apple gadget owners reach limits to data storage, they are prompted to pay monthly fees for digital locker space online at the Californian based-firm's iCloud service.

The lawsuit says: "Using these sharp business tactics, (Apple) gives less storage capacity than advertised, only to offer to sell that capacity in a desperate moment, eg when a consumer is trying to record or take photos at a child or grandchild's recital, basketball game or wedding.

"Each gigabyte of storage Apple shortchanges its customers amounts to approximately 400-500 high resolution photographs."

Lawyers behind the suit are seeking class action status along with punishments that include Apple turning over all profits from sales of gadgets at issue in the case.

Apple has so far declined to comment to the media on the matter.

Apple has been embroiled in countless lawsuits with tech rival Samsung over recent years. The smartphone and tablet makers have accused each other of infringing patents in intellectual property battles around the world.