Discovery Communications has announced that a lawsuit the company filed against Amazon on Wednesday for patent infringement is not a new case.
News agency Reuters reports that the company has revealed it had launched the legal challenge previously in 2009, but had since moved two patents to the separate corporate entity, Discovery Patent Holdings. Wednesday's complaint had arisen because of that move.
A spokesperson for Discovery said: "The new lawsuit was brought because the patents at issue in the original lawsuit were recently assigned to Discovery Patent Holdings LLC."
The lawsuit concerns the infringement of patent for an "Electronic Book Security and Copyright Protection System", allegedly used by Amazon's Kindle and Kindle 2 e-book readers.
The lawsuit specifically concerns technology used in the Kindle DX.
Discovery Holdings, which has requested a full-jury trial, has asked for royalty payments and an unspecified amount in damages.
According to tech news website Beta News, the patents also cover technology used in other e-book readers, including Barnes and Noble's Nook.