With luck there actually is a videotape, and Trump is more than fair game.
Certainly the belief that there are tapes is widespread and longstanding
And the former MI6 agent is not the only source for the claim about Russian kompromat on the president-elect. Back in August, a retired spy told me he had been informed of its existence by "the head of an East European intelligence agency".
Later, I used an intermediary to pass some questions to active duty CIA officers dealing with the case file - they would not speak to me directly. I got a message back that there was "more than one tape", "audio and video", on "more than one date", in "more than one place" - in the Ritz-Carlton in Moscow and also in St Petersburg - and that the material was "of a sexual nature".
The claims of Russian kompromat on Mr Trump were "credible", the CIA believed.
http://www.bbc.co.uk/news/world-us-canada-38589427?intlink_from_url=http://www.bbc.co.uk/news/topics/78080d81-2849-497e-bc3a-bf364626456b/donald-trump&link_location=live-reporting-story