The U.S. Justice Department is now investigating Chinese smartphone maker Huawei Technologies Co. Ltd. for potential violations of sanctions on Iran.

“It’s unclear how far the Justice Department probe has advanced and what specific allegation federal agents are probing,” said a report published Wednesday in the Wall Street Journal. The paper said it had spoken to people familiar with the investigation, so it looks like more hard times for Chinese technology companies in the U.S.

Earlier this month, the U.S. Commerce Department banned American companies from exporting to Chinese electronic form ZTE Corp. It was found that the company had not adhered to an agreement made with the U.S. government after it had been found guilty of illegally shipping goods to Iran and North Korea and fined $1.19 billion.

Both the U.K. and the U.S. have said that ZTE posed a national security risk. “China does not play by our rules, and we must be vigilant against Chinese threats to both our economic security and national security,” said U.S. Rep. Robert Pittenger.

Some reports suggest that such sentiments might be hyperbolic, but in February the CIA, FBI and NSA all said that Americans should not use Huawei phones as they could be used for espionage. A Senate Intelligence Committee had met and discussed the use of Huawei’s phones for spying on America.

At the time of that report, Huawei had overtaken Apple Inc. as the second-largest smartphone company in the world behind South Korea’s Samsung Electronics Inc., though it only has a 1 percent market share in the U.S. Nonetheless, with spying talk from government agencies on the table earlier this year, AT&T Inc. backed out of a deal with Huawei to launch its Mate 10 Pro flagship.

Talking of the measly market share Huawei has in the U.S., Senator Tom Cotton said, “That pleases me, although it’s not zero. And that’s where I’d like to get it.”

In a statement regarding the investigation, a Huawei spokesperson said, “Huawei complies with all applicable laws and regulations where it operates, including the applicable export control and sanction laws and regulations of the UN, U.S. and EU.”

Image: Maurizio Pesce via Flickr