Clear Food, part of Clear Labs, analysed 345 individual hot dogs and sausages from seventy-five different brands sold at ten food retailers. The findings showed that 14.4 per cent of hot dogs were problematic in some way.

Problems included the presence of ingredients not on the label and hygienic issues, such as the presence of human DNA.

Clear Food used next-generation genomic technology to analyze the samples at a molecular level, ingredient by ingredient.

In terms of substitutions, the study found evidence of meats not found on labels, an absence of ingredients advertised on labels, and meat in some vegetarian products.

Chicken was found in 10 samples, beef in 4, turkey in 3 and lamb in 2, in products that were not supposed to contain those ingredients.

Clear Food also found pork substitution in 3 per cent of the samples tested. In most cases, pork found its way into chicken and turkey sausages.

In terms of hygiene, Clear Food also found human DNA in 2 per cent of the samples. Two thirds of these samples with human DNA were in vegetarian products.