The US embassy in Moscow on Monday ridiculed a Russian television channel after it posted a picture of the ambassador crudely photoshopped into an opposition rally.

The Ren TV channel claimed in headlines that US Ambassador John Tefft "was sent to the opposition rally" held Sunday, posting a picture of him facing a media scrum with protesters in the background.

Russia's President Vladimir Putin has accused the United States of sparking protests against his rule, and state media frequently repeats the allegation, accusing protesters of taking money from foreign governments.

But the the US embassy said that the ambassador was nowhere near the protest and the "fake" picture involved a photo of the envoy at an event in February with the protest pasted into the background.

"Ambassador Tefft spent his day off at home, but one can end up anywhere thanks to Photoshop," the embassy said on its official Facebook page, posting joke pictures of Tefft in a Moon landing and at a hockey match.

"Russia's Ren TV published a fake," wrote embassy spokesman Will Stevens.

The Kremlin-loyal channel is part of the National Media Group holding which also owns Russia's most popular Channel One.

The channel backtracked on Monday, saying they merely shared a picture which was "launched by bloggers" and offered its "apologies due to publishing misinformation."

Russian channels have a history of publishing false information on their official social networking pages like Twitter, particularly about the conflict in Ukraine.

A recent tweet by the Zvezda channel, which is owned by the Russian defence ministry, took a photo of Ukrainian soldiers carrying a wounded comrade and pasted a picture of a cow on top of the soldiers body, headlining the story "Ukrainian troops steal cattle from civilians."

That tweet and the picture were deleted after a storm of criticism.