The U.S. International Trade Commission (ITC) has agreed to investigate if Apple has imported devices that infringe three patents held by AliveCor.

AliveCor filed the ITC complaint in April, alleging that Apple violated U.S. tariff law by importing certain Apple watches that infringe patents for its ECG technology. Mountain View, Calif.-based AliveCor wants the trade commission to issue a limited exclusion order and a cease-and-desist order against Apple, according to an ITC news release.

AliveCor filed a federal patent lawsuit against Apple in December 2020, alleging that Apple is infringing its patents by selling Apple watches that employ infringing functionality. Filing in the ITC “is one step, among others, AliveCor is taking to obtain relief for Apple’s intentional copying of AliveCor’s patented technology—including the ability to take an ECG reading on the Apple Watch and to perform heart rate analysis—as well as Apple’s efforts to eliminate AliveCor as competition in the heartrate analysis market for the Apple Watch,” AliveCor said in a separate news release.

AliveCor unveiled the ECG-equipped KardiaBand for Apple Watch in March 2016. It was a thin wrist band designed specifically for the Apple Watch that returned single-lead ECG readings and diagnostics that could be viewed through its app and sent to managing physicians. The device was cleared for use in the Apple Watch in November 2017.

AliveCor ended sales of its KardiaBand for use with the Apple Watch in 2019, when it debuted KardiaMobile 6L, a six-lead, handheld device FDA cleared to detect atrial fibrillation, bradycardia and tachycardia. Apple launched its own on-board EKG scanning and AF detection technology in 2018.

Apple did not immediately respond to a request for comment.