However, Facebook is insisting that the data in question never left people’s phones, and was not stored on Chinese servers. It also said it will wind down its deal with Huawei by the end of this week.

This all has to do with a Sunday New York Times report that detailed how Facebook has for years had partnerships with mobile device manufacturers, such as Apple and Samsung, that allowed the manufacturers to build software incorporating Facebook functionality. This software would typically also incorporate functionality from other sources such as email and other social networks, so that users could get all their messages and notifications in one place.

The issue is that this essentially meant giving that third-party software access to the data of not only the people using their phones, but those people’s contacts as well—typically without telling those contacts where their data was going. Indeed, Facebook did not publicly talk about these deals much, until the post-Cambridge Analytica spotlight fell on them.

Facebook has now said that it had such arrangements with four Chinese companies: Huawei, Lenovo, Oppo and TCL. However, Facebook vice president Francisco Varela said, the social network approved everything those companies built.

“Given the interest from Congress, we wanted to make clear that all the information from these integrations with Huawei was stored on the device, not on Huawei’s servers,” Varela said, as quoted by CNBC. That specification, it seems, is aimed at reassuring lawmakers and users that the Chinese had no access to the data.

“Like all leading smartphone providers, Huawei has worked with Facebook to make Facebook’s services more convenient for users,” a Huawei spokesperson said. “Huawei has never collected or stored any Facebook user data.”

U.S. intelligence chiefs earlier this year warned Americans against using phones made by Huawei, which are also marketed under the youth-oriented Honor brand. FBI Director Christopher Wray said Huawei’s access to the U.S. market “provides the capacity to maliciously modify or steal information [and] conduct undetected espionage.”

Huawei was founded by a former People’s Liberation Army engineer called Ren Zhengfei, and its overseas expansion has been largely funded by lines of credit from state-owned Chinese banks. Neither of these facts is particularly unusual for a Chinese company, but they have certainly fed into a perception that Huawei, like ZTE, is not to be trusted.

This article was updated to include Huawei’s statement.