The U.S. International Trade Commission will investigate Apple following allegations by Qualcomm that the iPhone maker is violating six of its non-standards-essential patents.

Qualcomm submitted to the ITC on July 7 a request to stop Apple from importing iPhone 7 handsets and other products infringing patents related to "envelope tracking, voltage shifter circuitry, flashless boot, power management circuitry, enhanced carrier aggregation, and graphics processing."

The Qualcomm patents at issue are:

No. 8,633,936
No. 8,698,558
No. 8,487,658
No. 8,838,949
No. 9,535,490 and
No. 9,608,675

Qualcomm also filed suit against Apple over the same six patents in the U.S. District Court for the Southern District of California. It also sued Apple for patent infringement in Germany.

The ITC request came less than three weeks after Apple added claims to a suit it brought against Qualcomm in January. In the new claims, Apple said Qualcomm violated a May ruling by the Supreme Court by essentially seeking payment twice for its inventions - through chip sales and royalties.

The dispute has an impact to Qualcomm's revenues. In April, the company lowered its revenue forecast by $500 because it stopped receiving royalty payments on iPhone and iPads. In July, it reported a 40 percent drop in net income to $800 million, compared to $1.4 billion from the same period last year.

In January, Apple sued Qualcomm for a billion dollars, claiming the chip vendor "insists on charging Apple at least five times more in payments than all the other cellular patent licensors we have agreements with combined."

Apple also filed suits against Qualcomm in China and the United Kingdom.