Heard 3AW this morning with the report that had been posted on their rumour file
I can confirm via talking with crews that a wheel axle separated whilst on taxi just short of the runway, it was noticed by another crew following nearby. The aircraft was then taxied back to the gate (at this point I'm wondering whether an engineer inspected it first before they made that decision, sounds dangerous and problematic to me). It is believed that corrosion was the cause but the CASA / ATSB investigation should pin point this.