A teenager accused of plotting to behead a police officer as part of a holiday terrorist attack also discussed planting explosives on a kangaroo, painting it with an Islamic State symbol and setting it upon the police, prosecutors said on Friday.
The teenager, Sevdet Ramadan Besim, 19, of Hallam, a suburb of Melbourne in Victoria State, on Thursday pleaded not guilty to four terrorism-related charges.
According to a prosecutor’s summary, Mr. Besim spoke online with a 14-year-old British boy last March about plans to attack and behead a police officer during a military parade.
Mr. Besim and the British teenager, who lived in Blackburn, England, also discussed packing a kangaroo with explosives and letting it loose on the police. All four charges carry the possibility of life in prison.
The Australian federal police said the plans for the attacks were discussed before last Anzac Day, which observes the landing of expeditionary forces from Australia and New Zealand in Turkey during the Gallipoli campaign of World War I.
Large-scale public ceremonies were planned for last April, the centenary of the landings.
Mr. Besim was arrested, along with four other teenagers, in raids last April and has been in custody since then. The police have that said they had all five men under surveillance and the raids were carried out because of a specific threat.
The police said Mr. Besim was motivated by an extremist ideology and he had expressed support for a terrorist organization.
He is due back in court next week. The other boy was sentenced by a British court in October.
The teenager, whose name was withheld because of his age, pleaded guilty at Manchester Crown Court in July to inciting terrorism overseas.
According to British prosecutors, he sent thousands of online messages to extremists in Australia , and it was an Islamic State recruiter, Abu Khaled al-Cambodi, who established contact between the boy and Mr. Besim, who was then 18.