The Australian Transport Safety Bureau says it is too early to say how close two Qantas planes came to mid-air disaster, in a near miss over South Australia on Friday.
The ABC reports a traffic control blunder resulted in one plane being given permission to fly towards the other, 20km west of Adelaide.
It has been reported the Airbus A-330s came within about 200 metres of a collision.
But a bureau spokesperson said that has not been confirmed by the team investigating the incident.
The ABC reports a preliminary report will be available in about a month, but the full investigation could take up to 12 months.
An air traffic controller has been stood down, which is standard procedure when an incident is under investigation.