A US politician called on Alphabet (Google) and Twitter to reveal details of data sharing partnerships with Chinese companies, following reports earlier this week about Facebook’s relationship with device makers.

Senator Mark Warner, who is vice chairman of the Senate Select Committee on Intelligence, said “since at least October 2012, when the House Permanent Select Committee on Intelligence released its widely-publicised report, the relationship between the Chinese Communist Party and equipment makers like Huawei and ZTE has been an area of national security concern”.

In a letter to Alphabet chief Larry Page, Warner wrote: “It has come to my attention that Google pursued various strategic partnerships with Chinese mobile device manufacturers including Huawei and Xiaomi, as well as Chinese technology platform Tencent.”

He called for details on the relationship between Google and Chinese companies, including “were ZTE, Lenovo and/or TCL among them” in addition to those already named. Warner is also seeking details of how and where data was transmitted and stored, including how the Android platform company would know if data had been sent from devices to other servers.

The letter to Twitter chief Jack Dorsey was similar, although without highlighting specific deals.

Earlier this week, Facebook acknowledged it had previously given device makers deeper access to its platform, as part of a strategy to get the social network integrated into smartphones from a wide range of vendors.

This sparked concern information marked private, including data from friends, could be accessed by a wider range of companies.

Unsurprisingly, with Chinese vendors having a strong position in the global mobile device market, Facebook confirmed companies based in the country were among those with which it offered deeper access.

The social networking giant has stated it is in the process of rolling-back such deals.