During OPSON VII, an EU coordinated action was run with the support of the EU Food Fraud Network across 11 European countries in order to detect fraudulent practices pertaining to tuna fish. This was the first time that such an action was carried out on a specific product.

The illicit practices included substitution and fraudulently selling tuna intended for canning as fresh. In this case, the tuna intended for canning was illegally treated with vegetable extracts containing high concentration of nitrites that altered its colour to give the misleading impression of its freshness. This can represent a serious risk to public health, taking into account that the modification of the initial colour can mask spoilage allowing the development of histamine responsible for the scombroid syndrome in humans. In total more than 51 tonnes of tuna were seized and more than 380 samples were taken.

Justice, police, customs and food experts were mobilised to investigate and to ensure the success of this operation in which 11 countries (Spain, Italy, France, Germany, Portugal, The Netherlands, the United Kingdom, Hungary, Liechtenstein, Norway and Switzerland) were involved. In some countries investigations took place on fishing vessels and in processing plants when, in other participating countries, extensive sample plans took place at distribution and retail levels.

In Scotland, the Scottish Food Crime and Incidents Unit (SFCIU) at Food Standards Scotland co-ordinated a European partnership approach involving the Food Standards Agency and a number of EU member states to undertake sampling and analysis of tuna. This amounted to samples being taken around Scotland by Officers from Environmental Health services in several local authorities.

Spain and France are also conducting judicial inquiries into tuna destined for canning and sold as fresh and on the illegal use of additives, however the results of which cannot be disclosed at this moment.

Operation OPSON is an international initiative co-ordinated by Europol and Interpol to encourage participating countries to hold a focused period of activity against illicit, counterfeit and sub-standard food.