Sophie Brown and her son Riley
The potentially deadly tablets were found inside the Minions-themed chocolate treat where children would normally expect to find a plastic toy.
It has since emerged that the pills are suspected to be Tramadol and MDZ tablets, to treat severe pain as end-of-life sedatives, after observations by a nurse. If taken, these are enough to kill a child or put them in a coma.
Two-year-old Riley Apps was struggling to open the plastic toy container so took it to his mother Sophie Brown, 22.
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The egg was thought to be a fake Minions brand
It's really, really frightening
But she was horrified when she discovered four colourful capsules and two white tablets marked with 'MDZ' – later suspected to be palliative care sedatives.
The shocking incident has sparked fears potentially lethal drugs could be sold to children across Britain if other eggs have been tampered with.
The mother-of-two immediately took the tablets to the police and informed the small independent shop where she bought them.
Officers have now launched an investigation after they confirmed the tablets were "over-the-counter medication”.
Ms Brown from Halifax is now warning parents to keep an eye on their children when they open 'surprise egg' chocolates.
She said: "He came running through and said 'mummy can you open it' because he had tried and wasn't able to.
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"I look down and it contained six tablets.
The tablets are potentially deadly
”When I saw them I couldn't believe it. I wrapped them up and took them to the police.
"If he had been able to open it himself it could have been lethal."
Ms Brown’s partner Ian King, 23, took Riley to the shop and they returned with the egg which he ate in the front room while she was in the kitchen on December 3.
It is believed to be a fake Minions brand – but the couple thought it was an official Kinder Egg product.
A spokeswoman for Ferrero confirmed the chocolate was not a Kinder product, adding: "This is a matter for the police and Ferrero UK has no comment to make on this subject."
Ms Brown who also has another son, aged five, added: "I'm just glad that Riley came and asked me to open it.
"Usually he will just play with the little toy himself. I usually think that I can leave him with it and not worry.
Police are investigating the incident
"He is always excited about what little toy he will find. I didn't know what they were. "The police took them and said they would be tested. They were just as shocked as me.
"I spoke to the shopkeeper and he was horrified.
"He's at that age where he would have definitely tried eating them.
"It's really, really frightening.
"I just want to warn other parents. They might give it to their child and not think and I just want to urge them to watch their children when they open the egg."
A spokesman for West Yorkshire Police said an investigation was underway.
He said: "Tests have been conducted on the substances found within the confectionery product. "The substances were found to be over-the-counter medication.”
Inspector Colin Skeath of Halifax Neighbourhood Policing Team added: "This appears to be an isolated incident and our enquiries are ongoing to determine how the medication came to be within the confectionery item."
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