The defence secretary has called on the public to report suspicious activity near military sites after a Russian TV crew prompted an alert at an Army base.
Gavin Williamson issued the warning after Timur Siraziev, of Channel One, was seen outside 77 Brigade's Berkshire base, the Mail on Sunday reported.
The unit works in social media and psychological operations.
An Army source said: "Timur Siraziev's suspicious behaviour was monitored by the base's security systems."
According to the Mail on Sunday, Mr Siraziev was seen with a cameraman repeatedly passing the barracks in Hermitage, Berkshire on the afternoon of 21 November.
Defence Secretary Gavin Williamson said: "We take the security of our bases and personnel incredibly seriously.
"If a member of the public sees anyone acting suspiciously in or around a military base it should be reported to the police as a matter of urgency."
With UK-Russian relations frosty in the wake of the Salisbury Novichok poisoning, GCHQ chief Jeremy Fleming warned earlier this year that Moscow posed a "real" and "active" threat to the international community.
Last month, the head of the British army, Gen Mark Carleton-Smith, described Russia as a "far greater threat" to UK security that the Islamic State group.
Mr Siraziev is listed on the Russian Embassy's website as Channel One's bureau chief.
When set up in 2015, 77 Brigade was touted as a unit that would help the UK to fight wars in the "information age" by helping to win hearts and minds.
It includes both regular troops and reservists.
Head of the Army at the time, Gen Sir Nick Carter, said the move was about trying to operate "smarter".