Some popular foreign cheeses contain more salt than sea water, say campaigners.

New research found halloumi, a Cypriot cheese, imported blue cheese and Greek Feta had salt levels exceeding seawater, while cottage cheese had the lowest.

An investigation into more than 600 cheeses sold in the top seven UK supermarkets found the average salt content was 1.7g per 100g of cheese, The Daily Mail reports.

Halloumi and imported blue cheese contained 2.7g, and Feta 2.5g - Atlantic seawater is equivalent to 2.5g per 100g of table salt.

Cheese spread, often given to children, contained 1.88g/per 100g of cheese, while cottage cheese had the least salt at 0.55g/per 100g

Campaigners said the new study, published in the journal BMJ Open, shows some cheese makers are not going far enough to reduce salt levels, putting their customers’ health at risk.

Cheese is one of the 10 biggest contributors of salt to the UK diet - cheddar and cheddar-style cheese being most popular – and the average person consumes 9kg (20 pounds in weight) of cheese every year.

Excess salt is a major contributor to high blood pressure, leading to heart disease and stroke.