Each year officials test products to ensure compliance with GM regulations on content and labelling of rice, soy and linseed strains.

The offending tortillas, imported via the Netherlands, were found to contain GM maize which was incorrectly labelled.

However the maize was EU approved and not deemed a health risk.

The find comes after concerns were raised over the potential contamination risk arising from the use of non-EU approved Canadian GM flaxseed.

Out of 26 products tested in the survey, nine samples were linseed.

All nine tested negative for the illegal variety. The authority believes this is due to effective contamination avoidance procedures.