By Sam Oliver

Published: 03:55 PM EST (12:55 PM PST)

The U.S. International Trade Commission is investigating a number of technology companies that make or use NAND flash memory, including Apple, after a patent-related complaint was filed.

Pennsylvania-based BTG International filed a complaint last month alleging that Apple -- along with Sony, Samsung, Dell, Lenovo and others -- violated the company's patents on non-volatile programmable flash memory chips. The company's claims were detailed at the ITC Blog.

"The complaint alleges that (the companies) unlawfully import into the U.S., sell for importation, and sell within the U.S. after importation certain MLC flash memory chips and products containing the same, which allegedly infringe BTG’s U.S. Patent Nos. 5,394,362, 5,764,571, 5,872,735, 6,104,640, and 6,118,692," the blog reads.

BTG International asserts that it owns inventions that involve "programming and reading flash memory cells that store more than a single bit of information per cell."

BTG International had already filed a patent infringement suit against Samsung in 2008 in a U.S. District Court in the Eastern District of Texas. An additional lawsuit was filed in July and includes Apple and the other defendants from the ITC complaint, minus Samsung. Both suits originate from Eastern Texas, where complainants often file in hopes of a favorable outcome.

Apple recently prepaid for a half billion dollars' worth of NAND flash memory from Toshiba, a company not included in the BTG International complaint. However, Apple has purchased flash memory from Samsung, which is named in the suit, in the past.