Too early to speculate laptops caused flight dip - ATSB

The Airbus A330-300, with 303 passengers and a crew of 10, experienced what the airline described as a "sudden change in altitude" north of its destination on Tuesday.

The mid-air incident resulted in injuries to 74 people, with 51 of them treated by three hospitals in Perth for fractures, lacerations and suspected spinal injuries.

The Australian Transport Safety Bureau (ATSB) has said an "irregularity" in one of the plane's computers may have caused the dramatic altitude change which hurled passengers around the cabin.

Laptops could have interfered with the plane's on-board computer system, it has been reported.

But the bureau says it's too early to make that judgment.

A spokeswoman said the bureau had not yet received an update from its investigators at Learmonth, near Exmouth in WA's north, where the plane was forced to land.

The flight data recorder and cockpit voice recorder had only just arrived at the ATSB's Canberra headquarters and were yet to be analysed.