Suspected Russian spies are generating photographs of fake faces with computer programmes to gather information on social media, experts believe.

An AP investigation has discovered a “vast army” of phony profiles on the professional networking site LinkedIn.

Some of the profile pictures appear to show eerily realistic faces that do not belong to real humans but were rather generated by a computer.

“Katie Jones,” supposedly a 30-year-old “Russia and Eurasia fellow” at the Centre for Strategic and International Studies in Washington, virtually befriended dozens of pundits at prominent think tanks as well as a senator's aide and a deputy assistant security of state.

In fact, the centre said it knew of no such fellow, and experts who analysed the profile photograph said it was probably fake.

One of those who accepted a friend request from the account was economist Paul Winfree, a former adviser to Donald Trump who is being considered for a seat on the Federal Reserve.

While it's unclear who created the profile, some believe a foreign intelligence agency was to blame.

Alarm bells were first raised when “Katie Jones” sent a friend request to Keir Giles, a Russia specialist with London’s Chatham House think tank.

Mr Giles found the request suspicious as he had recently been targeted by an espionage operation against critics of the Russian antivirus firm Kaspersky Lab.