WASHINGTON (AP) — The Justice Department unsealed criminal charges Monday against Chinese tech giant Huawei, two of its subsidiaries and a top executive, who are accused of misleading banks about the company’s business and violating U.S. sanctions.

The company is also charged in a separate case with stealing trade secrets from T-Mobile, according to federal prosecutors.

Prosecutors are seeking to extradite the company’s chief financial officer, Meng Wanzhou, and allege she committed fraud by misleading banks about Huawei’s business dealings in Iran. She was arrested on Dec. 1 in Canada.

U.S. prosecutors charge that Huawei used a Hong Kong shell company to sell equipment in Iran in violation of U.S. sanctions. Huawei had done business in Iran through a Hong Kong company called Skycom and alleged that Meng mislead U.S. banks into believing the two companies were separate, according to the Justice Department.

Huawei is the world’s biggest supplier of network gear used by phone and internet companies and has long been seen as a front for spying by the Chinese military or security services.

Prosecutors also allege that Huawei stole trade secrets, including the technology behind a robotic device that T-Mobile used to test smartphones, prosecutors said. A jury in Seattle ruled that Huawei had misappropriated the robotic technology from T-Mobile’s lab in Washington state.

The Huawei case has set off a diplomatic spat with the three nations, which has threatened to complicate ties between the U.S. and Canada. President Donald Trump said he would get involved in the Huawei case if it would help produce a trade agreement with China and told Reuters in an interview in December that he would “intervene if I thought it was necessary.”