When it's being sold at a cod price, that's a problem.
In the chip shops of northwest England, a quiet deception has been unfolding at the counter: cheap tropical catfish sold as the cod and haddock that generations of British diners have trusted. A BBC investigation, prompted by a Liverpool shop owner's complaint about unfair competition, used DNA testing to confirm that three in ten sampled shops were substituting pangasius — a fish costing a fraction of the price — without telling customers. The story is less about a single bad actor than about what happens when financial temptation meets regulatory silence and the near-impossibility of detecting fraud with the naked eye.
- A price gap of more than fourfold between catfish and traditional cod creates a powerful and ongoing incentive for unscrupulous chip shops to deceive customers for profit.
- DNA analysis at Liverpool John Moores University confirmed a 30% fraud rate among sampled shops — a figure one leading fish scientist called unusually high for this type of investigation.
- Regulatory responsibility is caught in a bureaucratic no-man's-land, with the Food Standards Agency deferring to local councils, most of which admitted they were unaware the problem even existed.
- Industry leaders are calling for mandatory species labeling on menus, but without enforcement mechanisms to back it up, honest chip shop owners are left competing on unequal terms.
- The burden of vigilance has quietly shifted onto consumers, who have no practical way to distinguish one white fillet from another without the kind of expensive testing unavailable at the counter.
What began as a tip from a Liverpool chip shop owner frustrated by competitors undercutting him through dishonest labeling became a revealing window into a quiet form of food fraud. BBC reporters combed through customer reviews — diners writing that the fish tasted unfamiliar, that it was "some cheap white fish" — before selecting ten chip shops in Liverpool and Manchester for DNA testing.
The financial logic behind the deception is straightforward. Pangasius, a tropical freshwater catfish farmed in Southeast Asia, costs around £3.40 per kilogram wholesale. Cod and haddock, the cornerstones of British fish and chips, cost roughly £15. That gap — more than four times the price — is enough to make the substitution tempting, especially when the fish is mild enough in taste and texture that most customers would never notice. When reporters asked staff at shops that listed only "fish" on their menus what species they were serving, the answers were evasive: "normal fish," "white fish," or a gesture toward a sign reading "traditional fish and chips."
DNA testing at Liverpool John Moores University confirmed what the reviews had hinted at: three of the ten samples were pangasius. Professor Stefano Mariani, who led the analysis, described a 30 percent fraud rate as unusually high in his experience. The catfish portions had been sold for between £3.80 and £5 — close enough to the price of genuine cod or haddock that customers had little reason to suspect anything was wrong.
Enforcement, it turned out, was nearly as murky as the labeling. The Food Standards Agency directed responsibility to local councils, but when the BBC contacted every local authority in the North West, ten did not respond and eleven said they were either unaware of fish fraud or had no active investigations. Only Salford had taken any action at all.
Andrew Cook, president of the National Federation of Fish Friers, acknowledged the problem likely runs deeper than most people realize. His position was clear: pangasius is a perfectly acceptable fish to serve — but only when it is honestly named and priced. Customers in his Chorley shop agreed. One woman said she would feel cheated paying cod prices for something else; a man whose wife is from Thailand said he would happily eat catfish — but only if he knew that is what he was ordering.
Without mandatory species labeling or routine testing, the investigation leaves the industry at an uncomfortable impasse: the incentive to deceive remains, the tools to detect it are expensive and rarely used, and the responsibility for policing it appears to belong to no one in particular.
A BBC investigation into chip shops across northwest England has uncovered a quiet but persistent form of food fraud: the sale of cheap catfish passed off as traditional cod or haddock, often without customers knowing what they were actually eating. The practice thrives in a gap between regulatory oversight and the difficulty of detecting it without expensive DNA analysis. The story began when a Liverpool chip shop owner contacted the BBC to complain about competitors undercutting him through dishonest labeling. That tip led reporters to examine dozens of online customer reviews, where diners had left comments expressing confusion about what species they'd purchased—"haven't a clue what type of fish it was," one wrote; "not cod or haddock, some cheap white fish," said another.
The financial incentive is stark. Catfish, a tropical freshwater species known as pangasius or river cobbler, is farmed in Southeast Asia and costs roughly £3.40 per kilogram at wholesale. Cod and haddock, the traditional staples of British fish and chips, run about £15 per kilogram. That gap—more than four times the price—creates an obvious temptation for businesses looking to cut costs. The BBC selected ten chip shops in Liverpool and Manchester for testing: five listed cod on their menus, four listed haddock, and three simply said "fish." When reporters asked staff at those three shops what species they were serving, they received vague answers—"normal fish" or "white fish"—or were pointed toward a sign advertising "traditional fish and chips."
DNA testing at Liverpool John Moores University revealed the reality. Three of the ten samples tested positive for pangasius. Professor Stefano Mariani, who oversaw the analysis, noted that a 30 percent fraud rate was unusually high in his experience with fish and chips investigations. The catfish portions had been sold for between £3.80 and £5, while genuine cod or haddock typically cost customers £4 to £6. The difference may seem small, but it compounds across hundreds of transactions, and it represents a breach of trust. Most consumers, Mariani explained, cannot visually distinguish one white fish fillet from another without specialized training. The taste and texture of pangasius are mild enough that many people would not immediately notice the substitution.
What makes the fraud harder to police is the fragmented responsibility for enforcement. The Food Standards Agency told the BBC that local authorities should lead investigations into isolated cases of mislabeling at chip shops. Yet when the BBC contacted every local authority in the North West, ten did not respond, and eleven said they were either unaware of fish fraud as an issue or had no ongoing investigations. Only Salford Council reported taking action, having issued a warning to a trader caught selling a different fish species as cod. The Chartered Trading Standards Institute acknowledged that while fish mislabeling is not widespread, "there are still some unscrupulous businesses" engaged in the practice.
Industry figures and customers alike expressed frustration with the deception. Andrew Cook, president of the National Federation of Fish Friers and owner of a chip shop in Chorley with nearly three decades of experience, said the problem "probably does go on" more often than people realize. He emphasized that pangasius is safe to eat and perfectly acceptable to serve—but only if it is honestly labeled and priced accordingly. "When it's being sold at a cod price, that's a problem," he said. Cook called on the industry to list fish species clearly on menus to maintain public trust. Customers waiting in his shop echoed that sentiment. One woman, 66, said she would expect cod or haddock when ordering fish and chips and would feel cheated if sold something else at the same price. Another man, 41, noted that while he would be willing to try catfish—his wife is from Thailand, where it is common—he insisted on knowing what he was eating.
The investigation exposes a gap between what consumers believe they are purchasing and what some businesses are actually serving. The practice is difficult to detect without DNA testing, which is expensive and not routinely performed. Most local authorities appear unaware the problem exists. The industry's own leaders are calling for transparency, but without clearer enforcement mechanisms or mandatory menu labeling, the incentive to cut corners remains. For now, the burden falls largely on customers to ask questions and on honest chip shop owners to compete fairly against those willing to bend the rules.
Citações Notáveis
In my experience with fish and chips, three out of 10 is quite a lot—I don't recall seeing this level of catfish.— Professor Stefano Mariani, Liverpool John Moores University
It is very difficult for a member of the public that is not a trained fish biologist to identify one fillet from another.— Professor Stefano Mariani
A Conversa do Hearth Outra perspectiva sobre a história
Why would a chip shop owner risk their reputation by selling catfish as cod? The penalty seems like it should outweigh the savings.
The math is simple: catfish costs a quarter of what cod costs per kilogram. If you're running on thin margins, that difference adds up fast. And the risk feels low—most customers can't tell the difference by looking or tasting, and enforcement is scattered. A local authority might never show up.
But the BBC found it in three out of ten shops. That's not exactly hidden.
No, but the BBC had a tip, did months of work, and paid for DNA testing. A typical customer just eats their meal. A typical local authority has no reason to suspect it's happening. That's the real problem—the gap between what's actually going on and what anyone is actively looking for.
The industry president said pangasius is fine to eat. So what's the actual harm?
It's not about the fish being unsafe. It's about the contract between a business and a customer. You order fish and chips expecting a marine species—cod, haddock, plaice. You're paying a certain price based on that expectation. When a shop substitutes a cheaper farmed catfish without telling you, they're breaking that contract and pocketing the difference.
Could this be solved just by requiring menus to list the species?
That would help, but it only works if there's enforcement behind it. Right now, the responsibility is unclear—the FSA says local authorities should handle it, but most councils don't even know it's happening. Without someone actively checking, a menu label is just a piece of paper.
What does the honest chip shop owner think about all this?
They're frustrated. They're losing business to competitors willing to cut corners. The industry president has been in the business for thirty years and says the trust of the public is everything. But trust is hard to maintain when some shops are gaming the system and getting away with it.