Much of the processed food sold in Dutch supermarkets still contains too much salt despite agreements with manufacturers, according to research by consumers association Consumentenbond.

Of the 90 products which the Consumentenbond has tested since 2007, 40 still contain the same amount of salt, the organisation said.

Some have even become saltier. For example, the Wagner Big Pizza Supreme now has 10% more salt than in 2013 and the makers of Old Amsterdam cheese have increased its salt content by 15%, the Consumentenbond said.

The organisation says the average Dutch person eats nine grammes of salt a day although just one gramme is important for good health and more than six grammes could be dangerous.

The organisation wants health minister Edith Schippers to take tougher action to ensure food firms lower the salt content in their products. The agreement signed by her and the industry last year is too full of holes to be effective, it says.