Scampi is sourced in a way that causes “extensive environmental damage”, a charity complaining to the UK competition authority has claimed.

Open Seas is disputing the sustainability of the popular seafood snack and has asked the Competition and Markets Authority (CMA) to investigate supermarkets who claim it is “responsibly sourced”.

The charity alleged “extensive damage” is caused from trawling the seabed with heavy nets when catching langoustines for scampi, and other marine life caught in the process is often wastefully discarded.

The British Retail Consortium said retailers were working closely with suppliers to “ensure products meet customer expectations on sustainability”.

It added: “Retailers are committed to sourcing scampi responsibly.”

However, Open Seas claimed describing the product as “responsibly sourced” breaches CMA guidance.

“We’ve raised these concerns with supermarkets, but they continue to sell scampi as ‘responsibly sourced’,” said Nick Underdown, head of campaigns at Open Seas.

A spokeswoman for Whitby Seafoods, which describes itself as the “home of scampi”, said: “We strongly dispute the claims made by Open Seas.”

CMA guidelines require marketing claims to be both truthful and accurate, and “clear and unambiguous”.

“Consumers should not be misled by products being marketed in this way,” Mr Underdown added.

Scampi is sold in the frozen aisles of supermarkets and, in the UK, is supposed to be made from langoustines. Although shrimp scampi, scallop scampi and other variations are also served in restaurants across Europe.

Mr Underdown told the BBC that there was “no effective vessel tracking” to reduce the harmful effects of catching nephrops, the group of marine life that predominantly makes up scampi ingredients.

“There is a vessel monitoring system but no means to monitor the composition of those catches,” he said, adding the level of “bycatch” – marine life caught unwittingly in the nets – can often include small animals and fish, which impacts the populations of that species in the future.

“Catching large volumes of young fish against scientific advice is not responsible. Trawling over fragile marine habitats is not responsible,” Mr Underdown said.

“Businesses failing to address these problems is not responsible. The way scampi is produced has all the hallmarks of an irresponsible fishery.”

Whitby Seafoods said that it has “a strong track record in building on the work of the scampi fishing industry in driving improvements to sustainability”.

In its complaint to the CMA, Open Seas said supermarkets’ claims that their fisheries were “responsible” was ambiguous, due to the term being “defined by a self-interested industry group without reference to international norms for defining responsible seafood”.

A spokeswoman for Whitby Seafoods, said: “The claim that scampi is ‘responsibly sourced’ is used in line with strict third-party guidance from the Sustainable Seafood Coalition.”

The Sustainable Seafood Coalition was founded by companies including M&S, Waitrose and Young’s.

Edward Whittle, Whitby Seafoods’ sustainability director sits on its steering committee alongside other seafood producers including Young’s and supermarket Sainsbury’s.

Whitby Seafoods states on its website that it is part of an industry-led Fisheries Improvement Project (FIP).

Project UK, which oversees the implementation of the FIPs for the industry, is funded by industry players including Marks & Spencer, Morrisons, Sainsbury’s, Young’s, Lidl, Co-op, Tesco and Whitby Seafoods itself.

But Mr Underdown told the BBC he was “extremely concerned about inaccurate self-reporting and the lack of progress being made by” the FIP for the scampi industry.

A spokeswoman for Whitby Seafoods, said: “We welcome the opportunity to explain to the CMA, or any other relevant party that asks us for clarification, about this important subject.”

The BBC has contacted major supermarkets and suppliers of UK scampi for comment.

Morrisons said on its website that it uses third-party certification to ensure its fisheries are “credible and sustainable”, with 99% of its farmed seafood “certified to global sustainable seafood initiative standards”.

Sainsbury’s meanwhile said it was the first-ever retailer to be awarded various accolades including one from the Marine Stewardships Council. M&S said on its site that it sits on the Board of Trustees for Fisheries Innovation Scotland and that it is an active participant in a number of Fisheries Improvement Projects.

Young’s said it is part of several sustainability organisations, while Tesco said it is working with wildlife charity WWF regarding its seafood sustainability aims.

The Co-op said it works with three independent schemes to verify its seafood sustainability.