AirAsia captain left seat before jet lost control - sources

Rescue team members walk as they carry the wreckage of a seat of the AirAsia Flight QZ8501 airliner at Kumai port in Pangkalan Bun, January 19, 2015. REUTERS/Beawiharta

SINGAPORE/JAKARTA/PARIS (Reuters) - The captain of the AirAsia jet that crashed into the sea in December was out of his seat conducting an unusual procedure when his co-pilot apparently lost control, and by the time he returned it was too late to save the plane, two people familiar with the investigation said.

Details emerging of the final moments of Flight QZ8501 are likely to focus attention partly on maintenance, procedures and training, though Indonesian officials have not ruled out any cause and stress it is too early to draw firm conclusions.