Seafood is one of the most valuable and highly traded commodities worldwide, and thus highly susceptible to fraud. The Norwegian fisheries sector is subject to a wealth of regulatory requirements ensuring an environmentally and economically sound fishery. Nonetheless, studies have shown that there exists a, at times significant, discrepancy between imports/landings and exports/domestic consumption. Parts of this gap can probably be explained by intentional acts of fraud, such as landings of illegal, unreported and unregulated (IUU) fish. However, as both the production process and the supply chain is highly complex, portions of the gap might also be attributed to non-fraud related issues, such as gaps in the regulatory framework, inaccurate reporting, production process errors, human error, or other unintentional factors. By combining a documentary study of the regulatory framework with a material flow analysis (MFA) and an in-depth case study, we map and analyse the Norwegian cod fishery supply chain to identify possible sources of discrepancies and inconsistencies. We estimate the scope of the discrepancy within the Norwegian cod fisheries, highlight weak points within the supply chain, and identify weaknesses within the regulatory framework regarding product registrations. The study shows that a combination of the different methods is valuable in understanding the complexity of the different recordings. By combining the methods, it is possible to test whether identified records are comparable or not, while contextual knowledge is useful in adjusting the analysis by identifying sources of discrepancies. Acknowledgement: This work was conducted in the framework of the EU Project FoodIntegrity.