Huawei is once again facing claims that it’s placing backdoors in networks. The Wall Street Journal reports that American contractor Business Efficiency Solutions (BES) has filed a federal lawsuit accusing Huawei of not only stealing technology, but pressuring the firm into installing a data backdoor for a law enforcement safer-cities project in Lahore, Pakistan. The system supposedly gave Huawei access to a database that helped it collect sensitive citizen and government data “important to Pakistan’s national security.”

BES alleges that Huawei insisted on creating a duplicate version of the Lahore network in Suzhou, China, that would provide direct access to the Pakistan data. While BES wanted permission from Pakistani officials before going forward, Huawei reportedly claimed it didn’t need permission and initially threatened to cut off the deal if BES didn’t move forward. The Chinese company later said it obtained permission, but apparently refused to provide evidence of this when asked.

The situation may not be clear-cut. Huawei told the Journal there was “no evidence” it had installed backdoors in any products. In a statement from earlier in the dispute, the company acknowledged the duplicate system in China but maintained that it was strictly a test version “physically isolated” from the real network, making it impossible to extract data. An overseer for the Lahore effort, Muhammad Kamran Khan, said an investigation was underway but that there wasn’t any evidence of data theft “so far.”

Whoever is telling the truth, the lawsuit highlights the ongoing concerns that Huawei might be aiding China’s surveillance goals. The company has long denied the allegations, and there isn’t yet “smoking gun” evidence that it has used backdoors to snoop on other countries. However, that hasn’t allayed suspicions that have led the US, UK and others to blacklist its technology. This case might only exacerbate Huawei’s situation, even if BES’ assertions don’t hold up in court.