The US importing of some iPhones built in China could be blocked after a US International Trade Commission recommendation that a trade judge find that Apple had infringed at least one of Qualcomm’s patents.

The chipmaker filed a complaint against Apple nearly a year ago, asking the commission to ban the import of iPhones containing rival chipmaker Intel’s modem chips, which help smartphones connect to wireless data networks.

At a hearing in Washington, the ITC said Apple had violated one of Qualcomm’s patents around battery-saving technology.

Throughout the hearings, Apple has argued that Qualcomm’s patents are invalid and that Intel-based iPhones should not be banned.