A former New South Wales School principal is at the centre of a fatal siege in Australia that left two police officers dead.

Four others are dead- a neighbour, and three alleged offenders, after a check up by four officers on a missing person report in rural Queensland turned deadly.

Courier Mail court and crime editor Kate Kyriacou says Nathaniel Train was a missing person, and that's how this started. The cause of Nathaniel's disappearance is still unknown. 

"Police were looking for Nathaniel on behalf of interstate police who asked them to go to the house to see if he was there, and of course when they arrived, they were ambushed." 

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