Qualcomm has accused Apple of downplaying the performance of its chipsets compared to rival Intel, as it hit back in the companies' $1 billion legal row.
Qualcomm responded this morning in a lengthy legal statement that centres on five main claims.
It said Apple threatened Qualcomm not to make any public comparisons between the performance of the Qualcomm powered iPhone 7, compared to Intel powered ones.
Qualcomm claims iPhones with its modem chipset outperformed those of Intel's. It cited research from testing firm Cellular Insights, which said "Qualcomm modems outperformed Intel modems by 30 percent overall and by 75 percent when the cellular signal is weakest".
In its second claim, Qualcomm said Apple deliberately chose not to use its chipsets to their full potential. It added: "[Apple] misrepresented the performance disparity between iPhones using Qualcomm modems and those using competitor-supplied modem."
The chipset maker also said Apple encouraged regulators around the world to attack Qualcomm's business by "misrepresenting facts and making false statements".
Ironically, one of these recent regulatory attacks has been from the Federal Trade Commission in the United States, which said in January that Qualcomm was charging Apple lower fees in a bid to get exclusivity for its products.
Its fourth accusation was that Apple "interfered" with agreements between Qualcomm and its licensees that make iPhones and iPads.
Finally, Apple has "breached agreements and mischaracterised agreements and negotiations" with the chipset maker.
Qualcomm is seeking unspecified damages from Apple, claiming it has backed away from promises in several agreements.
It is also requesting Apple does not "interfere" with agreements made between Qualcomm and licensees in future.
Don Rosenberg, Executive Vice-President and General Counsel of Qualcomm, said: "Over the last 10 years, Apple has played a significant role in bringing the benefits of mobile technology to consumers with its popular products and services. But Apple could not have built the incredible iPhone franchise that has made it the most profitable company in the world, capturing over 90 percent of smartphone profits, without relying upon Qualcomm's fundamental cellular technologies.
"Now, after a decade of historic growth, Apple refuses to acknowledge the well established and continuing value of those technologies. It has launched a global attack on Qualcomm and is attempting to use its enormous market power to coerce unfair and unreasonable license terms from Qualcomm.
"We intend to vigorously defend our business model, and pursue our right to protect and receive fair value for our technological contributions to the industry."
Apple was unavailable for comment.