Investigators are examining the fuel of a Tunisian twin-engine plane that crash-landed into the sea off Sicily killing 13 on board.
Both the quality of the fuel and the possibility that the fuel gauge was not working properly are being checked.
The Tuninter ATR-72 turbo-prop plane had 39 passengers and crew, 23 of whom were rescued. Three are still missing.
The plane was on its way from the southern Italian town of Bari to the Tunisian island of Djerba on Saturday.
Vito Riggio, the head of Italy's civil aviation body ENAC, told the Associated Press that the aircraft could have run out of fuel.
He said the plane had taken on very little fuel in Bari, where it had stopped for 20 minutes. Mr Riggio said the fuel cistern used to refill the plane in Bari had been tested and "the result was good", reports BBC News.
“At a certain point we realised one of the engines had stalled,” said passenger Rosanna di Cesare.
Speaking from her hospital bed where she was recovering with cuts on her arm, Di Cesare said she had been going to Tunisia on holiday with her boyfriend and his mother.
'I saw other passengers calling for help. They were screaming' “After a few minutes the other one stalled too and the plane started to lose altitude. It was like a film. Suddenly we hit and then it all went dark and the plane split apart,” said the 36-year-old from Taranto, near Bari.
“My boyfriend and I managed to swim out of the plane. The sea was rough and I grabbed hold of one of the wings while my boyfriend continued to look for his mother.”
She said she clung to a floating suitcase for a half an hour before she was rescued by a motorboat, informs IOL.
Hospital officials said to CBC, five survivors have serious injuries, including the pilot, who has a broken vertebra and injuries to the head and chest.
Investigators were inspecting the largest piece of fuselage on Sunday after the coastguard towed it to shore in Palermo.
Italian aviation officials said tests had ruled out impurities in the plane's fuel.
There was speculation that some fuel may have leaked or that a mechanical problem might have kept it from reaching the engines.