Much of the conspiracy theories surrounding the Estonia disaster can be traced to one person: Anton Surikov, a colonel in the GRU, according to major media reports. The so-called Felix report was written by Surikov in early 1995, and outwardly it appears to be from a serious research group, but the authors show it is a facade created by the intelligence service. According to Aftonbladet, Andreas Edevald described the core of the Felix report as alleging that Chechen criminals and high-ranking Estonians used the ferry to smuggle drugs and radioactive materials, then opened the bow visor to unload trucks due to a planned customs raid, causing the ship to sink.
The story from GRU was packaged in a way that made it changeable, but the core was that it involved a cover-up, with the main target being Estonia as part of a larger influence campaign. The report was reproduced in Russian and Estonian media and became central in reporting in the German Der Spiegel, which interviewed Surikov, and it eventually gained traction in Sweden, including in Expressen and 'Efterlyst'. According to Aftonbladet, Patrik Oksanen described how the reason for the sinking and what was smuggled changed over time, with Surikov involved in implanting these variations.
We dare probably say that we would have had a different public perception about M/S Estonia without GRU's contribution.
Distrust has continued to live on since then and reappeared in various forms, notably in Discovery's documentary 'The Find That Changes Everything'. After the accident, few Swedes believed in theories about a cover-up; the distrust came later. Anton Surikov died in 2009.
The full extent of GRU's involvement in spreading the conspiracy theories beyond the Felix report remains unclear, as does how much actual influence the report and Surikov had on public perception. In contrast, the cause of the disaster was clear relatively quickly: a bow visor that came loose in heavy seas, according to major media.
Briefly, the report says that Chechen criminals and high-ranking Estonians use Estonia to smuggle drugs and radioactive materials. Then they get information that customs plans a raid that night. Therefore, they must open the bow visor and drive out the trucks with radioactive materials, that is why the ship sinks.
Then both the reason why she sinks and what is smuggled changes. There, Surikov is also involved in implanting the change.
It has drawn energy and strength from something that chafes. The Felix report and GRU have contributed to that to the highest degree.