Egyptian experts are now examining the voice tapes from the cockpit of the EgyptAir jetliner which crashed on October 31st to see if they confirm suspicions that a co-pilot may have been responsible.
The experts flew to Washington this week when the National Transportation Safety Board announced it was about to turn over the lead role in the investigation to the FBI. The voice tapes on the flight recorder point to a deliberate series of actions by the person in the co-pilot's seat before the Boeing 767 crashed into the Atlantic with the loss of 217 lives.
The US authorities have postponed asking the FBI to investigate possible criminal action until the Egyptian experts have finished their scrutiny of the tape on which a relief co-pilot, First Officer Gamil al-Batouti, is apparently heard saying a Muslim prayer, "I entrust myself to God", followed by the words, "I have made my decision."
Members of Mr Batouti's family and many of the Egyptian media have pointed out the prayer is frequently used by devout Muslims and should not be interpreted as pointing to a suicide intention.
NTSB translators and the Egyptian experts are now working on a "literal factual transcript of all conversations and sounds", according to the board.
The Egyptian ambassador to the US, Mr Nabil Fahmy, has questioned if the words reported as on the voice tape are really on it. He told NBC's Today programme he had listened to the tape. When asked if it "sounds like a statement of suicide", he replied: "No, it does not, if it was said."
Meanwhile, a civilian salvage vessel, Carolyn Chouest, is sailing to the crash site about 60 miles south-east of Nantucket Island to try and recover further debris and bodies.