WASHINGTON (June 6): Facebook Inc. said it had data-sharing partnerships with four Chinese consumer-device makers, including Huawei Technologies Co., escalating concerns that the social network failed to safeguard users’ personal information.

The disclosure came after Mark Warner, the top Democrat on the Senate Intelligence Committee, said earlier Tuesday that he saw "a serious danger" that Facebook shared user information with Chinese device makers. Facebook said it was careful about the partnerships, which were designed to help smartphone makers build custom versions of Facebook’s app.

“Facebook’s integrations with Huawei, Lenovo, OPPO and TCL were controlled from the get go — and we approved the Facebook experiences these companies built,” Francisco Varela, the company’s vice president of mobile partnerships, said in a statement. “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.”

Facebook has disputed a report published Sunday in The New York Times that claims the company’s deals with about 60 phone and device manufacturers allowed them access to vast amounts of information on users and their friends.

"The news that Facebook provided privileged access to Facebook’s API to Chinese device makers like Huawei and TCL raises legitimate concerns," Senator Warner of Virginia said after Facebook’s disclosure late Tuesday. "I look forward to learning more about how Facebook ensured that information about their users was not sent to Chinese servers.”

Many US lawmakers have been skeptical of the company’s explanations of its latest purported data lapse, and demanded more accountability.

Senators John Thune and Bill Nelson, the Republican chairman and top Democrat, respectively, on the Senate Commerce Committee asked in a letter to Chief Executive Officer Mark Zuckerberg dated Tuesday for a full list of device makers with which Facebook had agreements. They also asked how the company verifies compliance with the agreements and whether Zuckerberg would like to amend his April testimony to the committee in which he said that users have "complete control" over how their data is shared.