Egypt plane crash investigators "90% sure" the explosion heard on the black box recording of the Russian flight was a bomb, a member of the investigation team told Reuters.
A memorial service for the 224 victims of the crash was be held in St Petersburg today.
Russia has sent the first of three teams of inspectors to Egypt to examine security conditions at airports there following the plane crash which killed 224.
Deputy prime minister Arkady Dvorkovich's announcement follows Russia's decision on Friday to suspend passenger flights to Egypt in the aftermath of the tragedy.
Sources said Sharm el-Sheikh's airport has an alarming record of gaps in security, including a key baggage scanning device that is often not working and lax searches at an entry gate for food and fuel for the planes.
One of the officials, involved in security for planes, also pointed to bribe-taking by poorly-paid policemen monitoring X-ray machines.
"I can't tell you how many times I have caught a bag full of drugs or weapons that they have let through for 10 euros or whatever," he told the Associated Press.
Terrorists would be able to bypass the wand-like devices being used to scan luggage in Sharm el-Sheikh, an expert has claimed.
Intelligence showed a "significant possibility" that the crashed Russian passenger jet was brought down by an explosion, ITV News was told.
As flights from Sharm el-Sheikh to the UK are delayed over bomb fears, we review what is known about the Egyptian plane crash tragedy.