Samples collected in supermarkets are being analysed to verify that the product corresponded to the fish species named on the label.
The operation was scheduled for this period leading up to Holy Week, when there is an increase in fish consumption in the country.
According to the inspectors, cod is usually one of the most substituted fish. In its place, the consumer may unknowingly be buying other species such as saithe and ling.
"Another example is with sole, which can pose as hake, panga, plaice and halibut. The consumer ends up paying dearly for an inferior product," said agriculture official Paulo Humberto de Lima Araujo.
During the operation, officials targeted products in the form of cuts (steak, slices, pieces etc.), which is how most fish substitutions are concealed. Samples were collected that had a suspicious appearance.
The inspections were made in the Federal District and the states of Rio de Janeiro, Paraná, São Paulo, Ceará, Rio Grande do Sul, Santa Catarina and Pará.
The samples will be taken to the National Agricultural Laboratory (Lanagro) of Goiânia, the Ministry of Agriculture. There, technicians will analyse the DNA of the fish to show whether or not the samples are fraudulent, and the results should be available in a month.
If fraud is proven, the fish suppliers can receive a fine of about US $15,000, or other punishments.
"In addition, companies can only return to the regular inspection system after verifying that they have implemented all corrective measures in their self-control plans, in order to ensure product traceability throughout the production chain, and after thorough evaluation of all product inventories," said Paulo Humberto.