A small US firm said Wednesday it has filed a lawsuit accusing Apple's online music store iTunes of using its patented technology for distributing digitized music and video.

ZapMedia Services Inc. is demanding unspecified damages and royalties from California-based Apple for supposedly using its intellectual property in iPod MP3 players and iTunes.

"The complaint alleges that ZapMedia Services' property is being exploited in a manner which is unlawful," ZapMedia attorney Steven Hill of law firm Hill, Kertscher & Wharton said in a written release.

A lawsuit filed in a US district court in Texas contends ZapMedia began work on a "system and method for distributing media assets to user devices via a portal synchronized by said user devices" in the late 1990s.

ZapMedia contends it met with Apple and "major technology and media companies around the globe" while crafting an online content delivery platform which it eventually patented.

Apple launched its iTunes digital content software in 2001.

ZapMedia said it tried to resolve the alleged patent violation complaint with Apple before resorting to a lawsuit. Apple declined to comment on the lawsuit as per its policy not to discuss pending litigation.