We Killed the Tsar?

According to the somewhat rabidly anti-British Graf zu Reventlow in “Der Vampir des Festlandes” the British government was complicit in the murder of Paul I of Russia in 1801. This surprised me at first and I was more than a little sceptical as Reventlow is a bit of a loon (let alone a socialist and a Nazi, but I repeat myself), but Wikipedia tells me otherwise, so it must be true…

Paul I actually sounded like a pretty reasonable Monarch, advocating chivalry for the nobles and better conditions for the workers, but he stood in the way of British trade so he had to go it would seem.
“with the alleged support of the British ambassador in Saint Petersburg, Charles Whitworth” is as good as saying that our government did it, as I doubt the ambassador took the initiative alone.
I’d never heard of this before, but I’m fairly sure that Vladimir Putin knows all about it.