More than a quarter of takeaway curries contained illegal levels of potentially harmful chemicals, a study showed today.
The survey of 66 curry takeaways in West Yorkshire found that 27% of them were using illegally high levels of artificial colour.
Nearly all the samples were coloured with a cocktail of tartrazine (E102), sunset yellow (E110), ponceau 4R (E124), carmoisine (E122) and allura red (E129).
The Food Standards Agency has called for these colours to be phased out of use because of their effects on children. An earlier study by researchers at the University of Southampton has shown evidence of increased levels of hyperactivity in young children consuming mixtures of some artificial food colours and the preservative sodium benzoate.
Graham Hebblethwaite, West Yorkshire's chief trading standards officer, said: "The Food Standards Agency is asking food and drink manufacturers to phase out the use of these artificial colours.
"The food industry has generally taken great strides to remove them but the message does not appear to have been heeded by the takeaway curry trade."
The law currently allows curry sauces to contain up to 500mg/kg of artificial colour but one sample was found to contain five times this level.
Sweets are allowed to contain up to 300mg/kg of colour but the study showed the worst curry contained the equivalent amount of colour as 3.6kg (8lb) of brightly coloured sweets.
West Yorkshire Trading Standards sampled the same curry, chicken tikka masala, at each takeaway.
None of the takeaways labelled colours in their curries and by law they are not required to.
Councillor Andrew Carter, of the Trading Standards Committee, said: "The law currently limits the use of these colours for health reasons. Using too much artificial colour is illegal.
"Those found to have been using too much colour will be revisited and if they haven't changed their ways they could be prosecuted."