An investigation against the youngest girl in the UK to be charged with terrorism offences has been dropped over fears she was a victim of trafficking.
The 16-year-old, who cannot be named for legal reasons, was accused of possessing manuals for making firearms and bombs.
She was arrested in October 2020 in the Derbyshire area of northern England and accused of holding extreme right-wing beliefs.
But, for the first time, British investigators halted the case after experts ruled she may have been groomed online by a US extremist.
She was scheduled to stand trial in August charged with six terrorism offences but the case was postponed to allow further investigations to take place after her legal team referred her to the nation's body for investigating trafficking and slavery.
This led to the Home Office's Single Competent Authority to conclude there were "conclusive grounds" she had been groomed by a male extremist in the US. Under the UK's modern slavery laws the conduct is classed as trafficking.
The case has now been discontinued by the Crown Prosecution Service on the grounds there is no realistic prospect of conviction.
Prosecutors had alleged the girl possessed a bomb-making video and a guide for making 3D-printed firearms.
Last week a 14-year-old boy became the youngest person in the UK to be convicted of terrorism offences.
Latest data revealed that 13 per cent of those arrested for terrorism offences in the UK were aged under 18.
Jonathan Hall QC, the independent reviewer of terrorism legislation, told the BBC that this case has wider implications.
"The internet is not only pulling more and more young people into criminal liability for terrorist offending, but may yield defences to criminal liability, or powerful public interest reasons why a child should not be prosecuted," he said.
"Issues of fault, dangerousness and criminal liability are still being worked out when dealing with online terrorism offending by children. This case has a wider implication.
"If criminal justice is not the right outcome, this begs the question whether there are adequate measures to deal with any abiding risk the child may present."