A scientific study showed that around a quarter to a third of fish products in Europe are mislabelled, the BBC reported on Tuesday (April 2nd).

Samples of fish products were tested at the Eurofins laboratory in Hamburg and showed that cheaper fish was being used as substitutes and then mislabelled on products.

Head of the fish department at Berlin's Rogacki Delicatessen, Ralf Teichelmann, said seafood mislabelling is a way for some suppliers to cut costs when faced with global price increases and decreased European Union fish catch quotas.

Teichelmann recommended buying high quality fish from local fish stores to avoid mislabelled fish.

In the United States, a study, compiled by non-profit Oceana, reported in February that one third of seafood on the market is mislabelled. The group sampled 674 retail outlets in the United States in 2010 and 2012, often finding cheaper, farmed fish being sold in place of wild-caught ones.

Kimberley Warner, a senior scientist at Oceana and the author of the report, said there were a lot of implications from the results of the study.

"Well there are potential health concerns, there are economic concerns. If you're paying a lot of money for a wild fish and you're getting a farmed fish as a substitute, you're being ripped off so many consumers are concerned from that end," said Warner. "There are potential health concerns as well. When you're eating something called "white tuna" but what you're really getting is a snake mackerel called escolar that can cause severe digestive effects. Not everybody is aware sushi restaurants are selling something called "white tuna" which is really escolar. So this is a concern from a health standpoint as well," Warner said.

Dr Stefano Mariani, a biologist at the University of Salford in the north of England, carried out one of the studies and told the BBC that, in Europe, cod was being substituted with cheaper fish such as pollock.

Presented by Adam Justice