Apple could be about to add movie rentals to its iTunes Store download service after a user stumbled upon what could be seen as hard evidence that film rental functionality is to be added.

"I was trying to report a problem via iTunes, and this pop-up for selecting a reason contained some interesting/revealing strings," Mac developer David Watanabe wrote alongside this iTunes screenshot posted on the Flickr image sharing website. "Looks like 'RentalMovies' will be coming to the iTunes Store."

Among the options for potential problems listed in the iTunes Store problem/refund reporting section were seven related to movie rentals. These included not receiving the movie, accidental purchase, poor content quality, duplicate purchase and bad metadata, as well as other options. The same complaints listings are available for other types of content bought on the iTunes Store.

Apple started offering downloadable films to buy about two years ago. Speculation that the firm would offer movies to rent, too, has been around ever since.