This thesis examines how alternative theories and conspiracy theories relate to the officialfinal report from the Joint Accident Investigation Commission (JAIC) regarding the sinkingof M/S Estonia in 1994. It also aims to determine what can be classified as a conspiracytheory versus an alternative theory. Through an argumentation analysis of two actors’alternative or conspiratorial theories, and a discourse analysis of the JAIC report, the studyexplores how these relate to one another. Andreas Önnerfors model of what constitutes aconspiracy theory is used as the theoretical framework. Stefan Torssell and Lars Ångström,two actors critical of JAIC, serve as sources; their arguments and statements are examined inrelation to JAIC’s conclusions about the disaster. The results show that Torssells alternativetheory fulfills all the criteria of a conspiracy theory, while Ångström is classified as analternative theorist with several conspiratorial traits. The thesis demonstrates that conspiracytheories can make use of the JAIC report, as it is perceived to contain shortcomings andcontradictions that may be interpreted as signs of something being hidden or insufficientlyinvestigated for the public. Another conclusion is that the boundary between alternativetheory and conspiracy theory is not always clear