Lawyers in the US have filed a class action suit against Apple Computer on behalf of owners of the iPod Nano, claiming the smooth surface of the unit is prone to excessive scratching.

The lawsuit alleges that Apple violated consumer protection laws as well as express and implied warranties and that Apple knew that there were design flaws with the Nano digital music player.

"The amount and durability of the resin applied as a protective coating during the Nano manufacturing process is clearly defective in that it is not sufficient to adequately protect the face of the Nano from extreme scratching and ultimately irreparable damage," the lawsuit says.