Initial forensic analysis of passengers' remains points to an explosion on Egyptair flight MS804, which crashed last week, sources in the Egyptian-led investigation committee said on Tuesday.
The sources, speaking on condition of anonymity, said that, so far, only small body parts, no bigger than the palm of a hand, have been recovered, indicating that an explosion ripped through the plane.
If the aircraft had hit the water intact the bodies would not have suffered such damage, the sources said.
The information was, however, officially denied by the head of the Egyptian Forensic Medicine Authority, who said it had "no basis in fact."
Neither the authority nor any of its staff had said anything of the sort, Hisham Abdul-Hamid said.
The Egyptair flight from Paris to Cairo, with 66 passengers and crew on board, crashed into the Mediterranean Sea about 290 kilometres off the Egyptian coast early on Thursday morning.
No distress call was received and Egyptian authorities have said the plane did not make contact with Egyptian air traffic control after passing out of Greek airspace shortly before crashing.
On Friday Egyptair announced that wreckage from the jet and some body parts had been recovered from the sea near where it went down. The airline says that searches for remaining debris and human remains are continuing.
Speaking in the aftermath of the incident, Egyptian Civil Aviation Minister Sherif Fathy said that the likelihood of a terrorist attack was "far higher than the likelihood that the plane developed a technical failure."
However, Egyptian President Abdel-Fattah al-Sissi has warned against rushing to conclusions as to the cause of the crash.
The sources in the Egyptian-led investigation committee, which also includes French aviation accident investigators and an Airbus technical expert, said that further forensic analysis was taking place which could determine whether the presumed explosion was caused by explosives on board the aircraft or some other cause.
DNA testing is under way to identify the remains so that they can be returned to relatives after the completion of the analysis, the sources added.
The crash came almost six months after a Russian passenger jet broke up in mid-air shortly after take-off from the resort of Sharm el-Sheikh in Egypt's Sinai peninsula, killing all 224 people on board.
Russian authorities said that the incident was caused by a bomb. The Islamic State extremist group, which operates in Sinai, claimed responsibility and published a photograph of a soft drink can which it said had been filled with explosives and smuggled onto the flight.
Egyptian authorities are still investigating that incident.