State Duma Deputy Sergey Kovalev sent an official inquiry to Moscow's internal affairs head V.V. Pronin regarding specific explosive discoveries in September 1999. The document cites media reports about a 'Gazelle' driver who claimed to have transported 'bags of sugar' that were later revealed to be explosives at Borisovskie Prudy and Krasnodarskaya streets. Kovalev asks for verification of a Mercedes trailer at the 51st km of the MKAD where the cargo reportedly originated. Additionally, the inquiry seeks details on the discovery of 3.5 tons of explosives in Kapotnya garages, as reported by MUR head Kirill Mizulin. These inquiries are significant to the 1999 apartment bombings narrative as they probe early leads, the 'sugar' cover-up, and the specific logistics of the explosive transport.