A two-year-old girl died after swallowing a toilet cleaner capsule, an inquest has heard.
Arietta-Grace Barnett, from Sarisbury Green, Hampshire, is thought to be the first child in the world to have suffered such an injury, the hearing in Winchester was told.
The girl, who is believed to have swallowed a Toilet Duck capsule, was rushed to Southampton General Hospital after she began vomiting a "bright pink" liquid on 28 June, last year.
But the toddler was allowed to leave hospital on 2 July before attending an outpatient appointment the following day.
She was readmitted a week later on 9 July after she began bleeding and died that day.
The coroner, Rosamund Rhodes-Kemp, said children had accessed the product, despite its claims of being child-proof.
She said: "The child-proofing wasn't child proof because it had definitely been tampered with at the top and according to mum, that was done by one of the children.
"It was possible for this to be opened, that is an issue and will have implications to manufacturers and parents about how they keep this type of product."
It is also, she explained, designed to slow-release "globules" of chemicals.
Paediatric surgeon Simon Keys told the hearing that if a chemical from the product had caused such a significant injury as suffered by Arietta-Grace, "that hasn't been described in a child before".
He added: "If this is what has happened to Arietta, this is the first time it has happened in the world.
"If this is the explanation for the injury, it's the first time it's been described, it's a tragedy clearly, it has wide implications for everybody in the medical community treating people with this type of injury and for the people making these products.
"The outcome was totally unpredictable and I do not think we can say for certain that this product caused that injury."
Dr Nicola Trevelyan, consultant paediatrician at Southampton General Hospital, told the hearing she had believed Arietta-Grace was showing signs of a viral gastroenteritis.
The inquest continues.
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