Chinese telecom giant Huawei Technologies Co. became the target of a criminal investigation by the U.S. Justice Department for alleged theft of trade secrets, The Wall Street Journal reported Wednesday.

Federal prosecutors are probing Huawei for allegedly stealing trade secrets related to the technology of a robotic device made by T-Mobile U.S. Inc, which was used in testing smartphones, the Journal reported, citing sources close to the matter.

The Journal said an indictment can be expected soon. Caixin could not immediately reach Huawei for comment.

The investigation arose out of civil lawsuits against Huawei filed by T-Mobile in 2014 accusing the Chinese company of misappropriating technology from T-Mobile, according to the report.

The case is another setback for Huawei, which is facing closer scrutiny by foreign governments related to its global initiative to roll out the next-generation 5G wireless telecom technology. Several countries, including Australia and New Zealand, have banned Huawei from their 5G network upgrades, citing national security concerns.

Last week, Polish authorities arrested then-Huawei executive Wang Weijing on charges of conducting espionage. Huawei subsequently terminated Wang’s employment.

Amid mounting pressures, Huawei’s founder Ren Zhengfei this week broke silence to dismiss spying accusations that have dogged the company. Ren said his company has never spied for the Chinese government and never would.

Related: Huawei's Founder Denies Spying