An Anzac Day terror attack in Australia plotted by a 14-year-old boy from his UK bedroom would "in all probability" have resulted in a number of deaths if it was not thwarted, a court has heard.
The teenager, now 15, from Blackburn, Lancashire, was radicalised on the internet by Islamic State propaganda and was said to be determined that police officers would be beheaded at a parade on April 25.
In July, the boy - thought to be Britain's youngest terrorist - pleaded guilty to inciting terrorism overseas.
Outlining the case at the start of a two-day sentencing hearing at Manchester Crown Court, prosecutor Paul Greaney QC said: "In short, from the bedroom of his parents' suburban home the defendant plotted an attack upon an Anzac Day Parade in Melbourne.
"He did so with an alleged Australian jihadist named Sevdet Besim, who we suggest used the online name 'Illyas'. Their plot was developed over the internet and the intention was that police officers should be murdered by beheading.
"It is clear that the purpose of this proposed attack was to promote the ideology and agenda of Isis. A striking feature of the case is that, at the time of the offence, the defendant was aged just 14.
"It is clear that he had been radicalised by Isis propaganda accessed by him over the internet and the evidence establishes that the contact with his Australian collaborator was instigated by a well-known Isis recruiter and propagandist named Abu Khaled al-Cambodi, himself an Australian, who has promoted the idea of terrorist attacks in his homeland.
"There is no doubt that there was a determination on the part of the defendant and Sevdet Besim that the plot should be carried through and the contact between the two included frequent references to the production of a martyrdom video by Besim for al-Cambodi which, no doubt, al-Cambodi intended to use for propaganda purposes.
"In the event, fortunately, the authorities here and in Australia intervened and a plot that would in all probability have resulted in a number of deaths was thwarted."