The US Department of Justice is reportedly investigating Samsung for patent abuse, according to a court filing from Apple.
The document, filed with the International Trade Commission, says that the "Department of Justice has opened an investigation into the manner in which Samsung has used - or misused - its declared-essential patents."
A Samsung spokesman, however, said the company "has not received any formal notification from the authorities."
"Samsung has been and remains committed to fair licensing of standard-essential patents," he said.
The filing squares with a June report from Bloomberg that said "the Justice Department will scrutinize Samsung Electronics Co.'s handling of industry-standard patent claims." Bloomberg's source, however, didn't know if the DOJ had formally contacted Samsung for more information.
That same article said the Federal Trade Commission would probe Motorola over its handling of essential patents.
Samsung is already under investigation outside the States. In January, the European Commission opened a formal investigation into whether Samsung has used its patents to "distort competition" in the European mobile market.
EU rules require companies that hold patents essential to the implementation of a standard to license them on fair, reasonable and non-discriminatory (FRAND) terms. So, if a company has a patent for something that is required to make all cell phones work - like network connectivity - it needs to make good faith efforts to license its technology to other companies, even direct rivals.
Most companies under fire on this issue - including Samsung - have said that they made efforts to license their technology, but have not been able to reach a workable deal. Rivals claim the prices being quoted are far too high. And round and round they go.
Apple and Samsung, meanwhile, are fighting each other over patents around the globe, including the ITC and two different cases in California. One of those California cases recently resulted in a landslide victory for Apple - to the tune of $1.05 billion. Samsung is currently appealing the verdict.
This week, however, Samsung prevailed when a Dutch court found that multi-touch features on Samsung smartphones and tablets do not infringe on an Apple patent, Reuters reported.
Recently, there were reports that Apple and Samsung's legal battles prompted Samsung to stop providing Apple with LCDs for its gadgets, but Samsung has denied it.