Steinberg and Khrustalev wrote in THE FALL OF THE ROMANOVS pps 390-1:
>> Solovyov, Boris Nikolaevich (b. 18993). Lieutenant, son of the treasurer of the Holy Synod N.V. Solovyov, member of Rasutin's circle in Petrograd, officer for commissions and adjutant to the chairman of the Military Commission of the State Duma Committee. In Septemember 1917, married the daughter of Grigory Rasputin, Maria (Matryona). Served as Anna Vyrubova's courier, delivering correspondence, money and gifts to and from the Imperial family in Tobolsk and planning the family's escape. While living in Pokrovskoe and later to Tiumen, he tried to bring the various efforts to free the tsar and his family under his own control. Stayed in close contact with Father Aleksei Vasiliev, the family's priest in Tobolsky, and with one of the family's maids. Arrested in March 1918. Many emigres later maintained that Solovyov was a provocateur, acting on behalf of the Bolsheviks in order to expose and abort genuine plans to free the tsar and his family. Died abroad.<<