Bottles of fake Head and Shoulders shampoo have been found for sale in shops across Northern Ireland, which contain potentially dangerous ingredients including "sex change" chemicals.
Discount shops have been unknowingly selling counterfeits of the popular haircare brand - with 2,000 bottles seized by Trading Standards officers across the province.
An investigation was launched by the Trading Standards Service after a woman in Antrim reported problems after she used what she thought was Head and Shoulders the hair of her five-year-old daughter, Immogen.
Nicole Patterson told BBC show Fake Britain: "The next day after using it, it looked like there were particles of paint in her hair.
"It wasn't until the second time then that there were instant speckles over her hair.
"Immogen then ended up with the scalp of her head was sort of peeling away. It wasn't like wee small bits of dandruff, it was quite big flakes and it would be the size of your small finger coming out of her hair."
She added: "So my worry was is my daughter going to be losing her hair here?"
The product was bought at a B&M Bargains store.
Ms Patterson complained to Trading Standards - and within weeks officers seized counterfeit shampoo at 15 discount stores across Northern Ireland.
An officer said: "We seized almost 3,000 bottles of the illegal product.
"We suspect though that there's quite a lot of counterfeit shampoo that appeared right throughout Northern Ireland that quite possibly has been sold to consumers from these high street retail premises."
Scientists carried out tests on the bogus products and found that they had a significantly different chemical make-up to the genuine product.
They contained high levels of the "sex change" chemical Diethyl Phthalate, which can affect reproductive health and can also be toxic to wildlife.
Ms Patterson's sample - contained ten times the level of Diethyl Phthalate seen in anything else.
One expert said: "You wouldn't want them in products you're putting in close contract with your children."
The fakes - which were also found in Home Bargains and in two Trago Mills' stores in Cornwall - contained no acidity regulator, which means there was nothing to stop uncontrolled chemical reactions occurring in the bottle.
They also had a known allergen Lilial, which can cause contact dermatitis.
Cornwall Trading Standards described the bottles as "extremely good counterfeits".
"They look almost identical to the real thing. It's not just one small part of the Head and Shoulders set of shampoos, it's every different type they are managing to counterfeit now."
Immogen was given medication from her doctor, but nearly a year later her other believes she still has symptoms and is considering legal action.
"I think when you go to a reputable store you don't expect to walk in and find counterfeit goods and that does make me really angry that I bought something that was counterfeit and actually used it," said Ms Patterson.
"It makes me angry that Immogen is left like this.
"I don't know what the cause is, what was in the shampoo and that is my main concern with Immogen, you know, I don't know what I've put in her hair.
"The effects are ongoing and something needs to be done about it."
B&M Retail said it was "shocked to discover that some counterfeit product had entered the supply chain from one of the wholesale supplies of the product".
The store added: "As soon as we were made aware the suspect stock was withdrawn from sale across all B&M stores.
"We are actively supporting the Trading Standards service to ensure a successful prosecution of the parties responsible further up the supply chain.
"This incident is the first in our 30 year history and we have taken steps to prevent a repeat occurrence."
Home Bargains said it had been trading for over 35 years and never had an incident of this nature.
Trago Mills said: "We purchased this particular product in good faith, from a trusted source, and we were one of a number of wholesalers and retailers, worldwide, who received it.
"The copy was so advanced that it took rigorous testing to identify it as a copy."
Damien Doherty, Area Inspector for Trading Standards in Northern Ireland, said: "Fake goods will not be subject to the same stringent safety tests as legitimate brands. Counterfeit shampoo has been known to cause serious rashes, allergic reactions and in more serious cases even cause burning to the skin.
"Trading Standards are warning consumers to be vigilant and keep an eye out for any tell-tales signs such as poor packaging, strong chemical smells, or cheap prices.
"Counterfeit goods are a big business, a drain on the economy and closely linked to organised crime. These items were being sold from major retail locations within Northern Ireland. Consumers expect to buy goods in confidence from traders they trust. We expect all traders to be diligent when buying stock and carrying out the appropriate checks on their supply chain.”
"Businesses or individuals involved in selling counterfeit goods are being warned they will have the goods seized and may face prosecution with the maximum penalty being ten years' imprisonment."
If you suspect that you have purchased counterfeit goods you should report the matter to Consumerline on 0300 123 62 62 or at www.consumerline.org.