The Commerce Department in 2016 issued an administrative subpoena aimed at Huawei, China's largest maker of telecommunications equipment, seeking information about whether it was sending US technology to rogue nations including Syria, Iran and North Korea.
The U.S. Treasury Department's Office of Foreign Assets Control, or OFAC, which enforces sanctions, and the Department of Commerce are also looking into Huawei's transactions.
News of the Justice Department probe follows a series of USA actions aimed at stopping or reducing access by Huawei and Chinese smartphone maker ZTE Corp to the US economy amid allegations the companies could be using their technology to spy on Americans.
Earlier this month, the Commerce Department banned ZTE, China's second-biggest network equipment maker, from buying USA -made components as punishment for violating a sanctions settlement over transactions with Iran and North Korea.
Major US telecoms companies have already steered clear of the two Chinese firms, sometimes on the strong suggestions of US officials.
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Huawei is hardly a stranger to pressure from the United States government and this is just the latest in a string of efforts to discredit the Chinese OEM.
In April, the Federal Communications Commission (FCC) announced that it would consider policies to stop using portions of its funding on products from companies that pose a potential national security threat.
Schloss, the Huawei spokesman, said those allegations aren't true. After all, Huawei has been in the U.S. government's cross hair perhaps longer than ZTE.
Issues and warnings against Huawei have come from presumptions that the company has ties to the Chinese government. The company is also the world's No. 3 maker of smartphones.
Optical-technology stocks are having a second really bad week after the U.S. Department of Justice opened a criminal investigation into China's privately held Huawei, which buys parts from the optical companies.