Few products are as local to Cornwall as clotted cream – yet one of the country's best-known brands travels 340 miles to end up on shelves near where it is made.

Rodda's products are made at a creamery in Scorrier, but are sent up to a distribution centre in Avonmouth, near Bristol, before coming back down to the Tesco store in Redruth – two miles away from the dairy's base.

Yesterday, one environmental group called on supermarkets to radically overhaul their distribution practices to cut back on food miles, as the revelation adds to mounting pressure. Last week, the Western Morning News reported that Ginsters Pasties travelled 240 miles from the bakery in Callington to a Tesco store which is just two doors away.

And now it has emerged that pasties delivered to the Callington Co-operative store, a mile from the factory, have travelled 250 miles to Portbury, near Bristol, before they reach its shelves.

Nicholas Rodda, whose great, great grandfather Thomas Rodda began selling cream at farmers' markets in 1890, admitted the founding father would be "surprised" at the round trip the clotted cream now takes.

He said: "It does sound crazy, but it does make sense. It's complicated."

Consumers have expressed bemusement that brands which cash in on their Cornish credentials are taking such long delivery routes. St Endellion Cornish Brie, made by Cornish Country Larder near Newquay, is sent to a depot in Taunton, Somerset, and then on to Avonmouth, before some of the stock ends up back in Cornwall. Meanwhile, sardines landed in Cornish ports travel outside the county before being sold in its supermarkets, meaning they are significantly less fresh than if they were transported directly.

Supermarkets claim that regional depots are the most efficient and eco-friendly way of transporting goods.

But yesterday, Maurice Spurway, Exeter coordinator for Friends of the Earth, branded the situation "ridiculous", and said supermarkets had failed to tune in to the public's desire for fewer food miles and more genuinely local produce.

He said: "There's an upsurge in terms of farmers' markets and allotments – people are growing their own food. Supermarkets are completely behind the curve.

"There's no doubt about it, it's absolutely essential for us to reduce food miles if we're going to stop runaway climate change."

The distribution situation has left small-scale businesses bemused. Ann Arnold, of the Pasty Stop Bakery, in Callington, described it as a "funny way of doing business", while Elaine Ead, of Padstow's Chough Bakery, called for a rethink on how food is distributed.

Tim Lang, professor of food policy at the University of London, first coined the phrase "food miles".

He said: "At one level it's completely absurd, but it is alas the reality of modern logistics, which is based on cheap oil, the motorway system and mass production. If people don't like it they are going to have to be prepared to pay for a more sustainable system of logistics."

A Co-operative group spokesman said lorries going to and from every individual supplier would mean "tens of thousands" of extra vehicles, resulting in an increased carbon footprint and traffic congestion.

Tesco said the method was the most efficient delivery network. He said: "If it were more efficient to make separate deliveries to local stores from national suppliers we would do so. But with more than 2,000 stores in the UK and an average Tesco superstore carrying 40,000 different lines, a centralised distribution system is more practical and efficient."