A joint trading standards operation involving 10 local authorities across the West Midlands included Britain's balti capital, Birmingham. It found that 36 of the 70 curry dishes tested by officers contained illegally high levels of artificial additives.
Some meals, such as tandoori chicken and chicken tikka masala, contained up to 16 times the recommended amounts of additives.
Repeated over-exposure to the colourings - tartrazine (E102 yellow), sunset yellow ( E110 orange) and ponceau 4R (E124 red) - can lead to allergies and asthma.
Fines of up to pounds 20,000 can be imposed and repeat offenders have been warned they could face prosecution in the future.
Dr Frank Hollywood, assistant analyst for Staffordshire County Council, said: "The worst dishes tended to be chicken, particularly tandoori and tikka masala dishes. The tests confirmed, as expected, that colourings were being overused. We are taking this seriously. Food allergies can cause a number of different reactions from rashes to boils."
Only sauce is subject to legislation; meat, poultry and rice are exempt. Now the councils want a change in the law.
Javid Choudhary, secretary of Birmingham's Asian Balti Restaurant Association, said: "I have been in the business for 13 or 14 years and have never heard of anyone getting ill from colouring. For some dishes [artificial colouring] is needed, otherwise it would look bland."
Gail Pollard, allergy dietician at Middlesex Hospital in London, said: "I must admit I have never had a patient come to me because of a problem with balti curries. But food allergies are very specific to the individual."Reuse content