Parents have been warned to be on their guard when buying Christmas presents for their children after dangerous levels of chemicals linked to cancer, infertility and asthma were found in counterfeit toys. Fake dolls based on Angelina Jolie's character in Disney's Maleficent film were discovered to contain 18 times the legal limit of phthalates when they were seized in Warwickshire in November.

Counterfeit figurines based on Disney film Frozen, seized by Trading Standards in January from shops in Pontefract and West Yorkshire, were also found to contain the dangerous chemicals.

The use of phthalates in toys is strictly regulated in the EU with manufacturers legally required to ensure they contain no more than 0.1% of the substance. Toddlers chewing toys with higher levels of the chemicals – used to make plastics more flexible – can develop long-term health problems, including cancer, infertility and asthma.

Robert Chantry-Price, of the Chartered Trading Standards Institute, said: "It is frightening to think that large quantities of phthalates are still being used in children's toys, especially when it can cause such serious long-term consequences to a person's health. Phthalates are carcinogenic, mutagenic and can cause reproductive problems but, despite legislation to the contrary, significant amounts of these substances can be found in a wide range of toys and child care products.

"If these toys fall into the hands of very young children or babies, it's more likely they will chew on the plastic and consume the chemicals. Trading standards services are continuously working to tackling the issue but it is vital consumers remain vigilant too."

Parents have been advised to be wary of toys being sold at significantly reduce prices, only buy from reputable shops and check the packaging for the distributor's details and a CE mark.

The dolls are just the latest in a long line of fake goods – including swimming goggles, fancy dress make up, false nails and loom bands – to be seized because of the illegal levels of phthalates. Trading Standards officers also recently seized some 15,000 hoverboards – set to be another popular gift this Christmas – after they were found to pose a fire risk.

A report published earlier in December found £174m ($260m) is lost to counterfeit toys and games each year in the UK alone.

loom bands
Fake loom bands seized in the UK were also found to contain dangerous levels of phthalates