The sound of an explosion can be heard on the black box recorder of the downed Russian jet, according to reports in France.
The France 2 TV channel quotes an investigator with access to the black box - but the country's BEA accident and investigation body said it could not confirm his claims.
If correct, the report confirms UK intelligence suggesting a bomb was smuggled into the hold of the Russian jet that crashed in Egypt last weekend, killing all 224 people on board.
The US has announced new measures to tighten air security and Russia has now followed the UK in suspending flights to Egypt.
The discovery has created a diplomatic row between the UK and Russia, who, having previously played down Islamic State claims of responsibility, want to see the intelligence.
Western intelligence sources who spoke to Reuters said the evidence was not categorical and there was no hard forensic or scientific evidence to support the bomb theory.
As the investigation into the cause of the disaster continues, flights from Sharm to the UK have resumed in the face of heightened security.
It has also been announced Britain will set up a small military operations team in Egypt to monitor extremism in the region.
Stranded
Thousands of passengers could be stranded in Sharm El Sheikh over the weekend after a day of chaos that saw rescue planes performing U-turns in mid-air.
The first planes carrying holidaymakers have begun to land in the UK, but the vast majority of those tourists who thought they would be coming home were left frustrated at the terminal.
Meanwhile, Russia is suspending flights to Egypt amid growing evidence that the jet was blown up by a terrorist bomb.
Vladimir Putin - who had previously dismissed claims of Islamic State involvement in last weekend's Metrojet disaster - said he was ordering his government to draft a plan for getting some 45,000 Russians currently in the country home.
The Russian president's U-turn came a day after he said Britain was jumping the gun by stopping flights - but the Kremlin insisted the move should not be treated as a sign that Russia has been convinced terrorists were responsible.
British PM David Cameron - who has spoken to Russian President Vladimir Putin twice since the crash - has said it is "more likely than not" that the jet was brought down by a bomb.
The Russian plan was announced as the Egyptian Ambassador to Ireland condemned a decision to halt Irish airlines operating to and from Sharem el Sheikh Airport until further notice.
Ambassador Soha Gendi said she notes "with great concern" the decision taken by Irish authorities.
In a statement, she said such a decision should only be made after investigations into the plane crash are concluded.
"We want this investigation to be completely transparent which can only lead us to the truth" added Ms Gendi.
She also said Egypt welcomes the participation of an Irish team in the investigations to check sites and participate in the procedures of recovering information from the carrier's black box.
But she claims this will create unnecessary worry among tourists.
The Minister for Foreign Affairs is urging any Irish citizens in Egypt who may be concerned about developments to contact the Irish Embassy in Cairo.
Minister Charlie Flanagan says his department has provided advice to a very small number of citizens who have made contact with the Consular Assistance Unit in Dublin or the Embassy of Ireland in Cairo seeking information.
He says there are currently no Irish tour operators with package holiday groups in Sharm El Sheikh.
The Department of Foreign Affairs is continuing to monitor the situation in Egypt through the Embassy in Cairo and is in close contact with EU colleagues.
They will continue to review and update travel advice as appropriate.
It is estimated that there are as many as 170 Irish people in Egypt.
