Environmental law organisation ClientEarth today published a report which claims that supermarkets which use labels such as "sustainably sourced", "protects the marine environment" and "responsibly farmed" were often misleading or unverified.
The group found that a total of 32 products it examined out of 100 carried false claims about the product.
ClientEarth named Tesco, The Co-operative, Lidl, Marks & Spencer, Sainsbury's and Waitrose as being among those stocking products in packaging featuring inaccurate claims.
The group also claimed "Dolphin friendly" labels featured on tinned tuna that was caught in areas where there was often no threat to dolphins, masking and failing to mention the harmful effects the tuna fishing method had on other threatened species such as turtles and sharks.
ClientEarth chief executive James Thornton said: "It would be shocking to find out that the free-range chicken you bought was actually battery farmed. Discovering the fish you're eating, which is labelled as responsible or environmentally friendly, actually led to the deaths of threatened species also leaves a bad taste in the mouth.
"Consumers need to be able to trust labels but in reality claims such as "sustainably sourced" or "responsibly farmed" are often misleading. The purchasing power of consumers is critical to stopping overfishing.
"We would like all supermarkets that have the misleading claims on the products we've identified to remove them as soon as possible or to prove them with evidence. If they don't do this, complaints can and will be made to the Office of Fair Trading arguing breaches of consumer protection laws."
The report calls for tighter regulation of fish labelling, including EU standards for environmental claims about fish products similar to those used for organic items.
It also recommends that the UK's Advertising Standards Authority extends its remit to cover packaging and labels as well as published advertisements.
Sainsbury's said all of its claims were verified by the Marine Stewardship Council while Waitrose also insisted that all its fish was sustainably sourced.
The Co-operative Group said all of its own-brand fish complied with its "strict" Responsible Fish Sourcing Policy.
A Tesco spokesman said: "We're constantly reviewing our labelling to give our customers better and clearer information and we expect to make further changes to our tuna labelling in the coming months."
Paul Willgoss, Marks & Spencer head of food technology, said: "We're delighted to see that Greenpeace have recognised all of the work we have done to ensure we have the most sustainable fish available for our customers to enjoy. We know that responsible fish sourcing is really important to our customers and we want to make it as easy as possible for them to buy food they can trust."
The Yorkshire Post has been running its Clearly British campaign for the past few years to encourage politicians and retailers to commit to more accurate labelling of food.
CALL TO WITHDRAW TINNED TUNA
Environmental charity Greenpeace has called for food company Princes to withdraw all of its tinned tuna because of "misleading" labels which say the company is committed to fishing methods that protected marine wildlife.
According to the environmental campaigners, the majority of Princes tinned tuna is caught using massive nets and devices which the tuna instinctively gather round, but which attract and catch many other species, including endangered sharks, and juvenile tuna fish.
David Ritter, head of Greenpeace's oceans campaign, said: "Endangered sharks and other species are killed every year while catching tuna to be put in tins."
A Princes spokeswoman said the firm was committed to a review of a its labelling practices and would examine its environmental claims as part of this.