The U.S. International Trade Commission (USITC) has commenced an official examination into four copyright complaints filed besides Apple by PC graphics hardware manufacturer S3 Graphics, which asked the agency to block Apple from importing the iPhone, iPad and other products into U.S.

The USITC on proclaimed it would investigate the May 28 supposed section 337 complaint filed by S3, based in Fremont, California. The complaint claims that Apple has infringed four S3 copyrights connected to electronic devices with image dispensation systems and connected software.

The copyrights engage image compression and decompression software, and Apple distributes a software development kit with the similar technology modified to utilize in its PCs, the S3 complaint said.

S3 has asked the USITC to block the import of iPod Touch with the MacBook, in adding to the iPhone and iPad, as per to the complaint. Legislatures of S3 and Apple didn't instantly react to a demand for comments.

S3 applied for a copyright for the image compression technology in October 1997.