LONDON/SAO PAULO—An obscure Hong Kong-registered company stands at the center of the U.S. criminal case against China’s Huawei Technologies and its chief financial officer.
U.S. authorities allege the giant telecom-gear maker used the firm to skirt American economic sanctions on Iran between 2007 and 2014. Huawei has said it sold the business in 2007 and denies any wrongdoing.