Whether this was actually Rasputin's intent or whether he was simply concerned about the huge number of Russian casualties (as the Empress's letters indicate) is in dispute, but it is clear that the British perceived him as a real threat to the war effort.

There were two officers of the British Secret Intelligence Service (SIS) in Petrograd at the time, Oswald Rayner and Stephen Alley.

[15] This account is further supported by an audience between the British Ambassador, Sir George Buchanan, who knew about an assassination attempt before it happened,[16] and the Emperor Nicholas II of Russia, when Nicholas stated that he suspected "a young Englishman who had been a college friend of Prince Felix Yusupov, of having been concerned in Rasputin's murder ...".

[17] The second SIS officer in Petrograd at the time was Captain Stephen Alley, born at Arkhangelskoye Estate near Moscow in 1876, where his father was one of the prince's tutors.

The archives of the MI6 do not hold a single document linking Rayner, Hoare, or any other British agent or diplomat to the murder.

Confirmation that Rayner met with Yusupov (along with another officer, Captain John Scale) in the weeks leading up to the killing can be found in the diary of their chauffeur, William Compton, who recorded all visits.

[22] "Additionally, Oswald Rayner translated Yusupov’s first book on the murder of the peasant, sparking an interesting possibility that the pair may have shaped the story to suit their own ends.

"[23] Newspaper reporter Michael Smith suggested that British Secret Intelligence Bureau head Mansfield Cumming ordered three of his agents in Russia to eliminate Rasputin in December 1916.

[26] Hoare, Rayner, and presumably the rest of the mission, knew of the plot ...[27] In 1934 he compiled an English translation of Yusupov's book, Rasputin; His Malignant Influence and His Assassination.