Huge amounts of cheap fish are being passed off in Britain as more expensive varieties as consumers fall victim to a 'murky and complex' cost-cutting scam, new research revealed today.
Seven per cent of cod and haddock - the staple of British fish and chips - are being mislabelled in supermarkets, shops and restaurants in a worrying parallel to the horsemeat scandal.
A similar study in the Republic of Ireland found that as much as a quarter of products were actually completely different species, while that figure rose to as much as a third across Europe as a whole.
Widespread deception: Seven per cent of fish being sold as cod and haddock in Britain are actually cheaper varieties, new research has found
In the United States, around the same proportion served in New York restaurants were not what they said on the menu.
Scientists who have studied the issue believe mislabelling of fish is too widespread not to be fraud.
Dr Stefano Mariani, a biologist at the University of Salford in the north of England, which conducted one of the studies, told the BBC: 'We noted that there were some suppliers that were consistently handling fish that was proven to be mislabelled, which suggests that a lot of mislabelling occurs before the fish gets delivered to the supermarket.
'Consumers should be able to go to a shop and know they are eating what they paid for.'
He found that cod in Britain and Ireland was being substituted with cheaper fish like pollock and Vietnamese pangasius, which is farmed in estuaries in South-East Asia.
More transparency needed: Researchers are now calling fopr tougher regulation and more effective labelling, so that fish can be sourced and traced
Much of the world's supply of frozen fish is produced in China which means that most of Europe's produce is flown into a Frankfurt airport rather than arriving by boat.
Ominously, the firm that tests the fish there, Eurofins laboratory in Hamburg is finding some species that have never been in food chain before.
Its Director of Scientific Development, Dr Bert Popping said: 'The authorities at the airport in Frankfurt have found some new species - species which have not been caught previously; fish species which have not previously entered the food chain; which have not previously been commercialised'.
Researchers are now calling for tougher regulation and more effective labelling, so that fish can be sourced and traced.
The horsemeat food-labelling scandal began when Irish food inspectors announced in mid-January that they had found horse in frozen beef- burgers made by firms in Ireland and Britain, and sold by a number of supermarket chains including Tesco, Iceland, Aldi and Lidl.
Since then, a growing number of stores and companies across Europe, including Findus and Nestle, have recalled beef ready-meals after tests found they contained horse DNA.
Minced beef supplied to hundreds of hospitals, schools, hotels and care homes by caterer 3663 was also recalled because of horsemeat contamination.