According to new figures by the French Interior ministry, published in daily Le Monde, seven French nationals are killed every month fighting in Syria.
The protracted conflict has redrawn battle lines in the Middle East and pitted Islamic State militants against forces loyal to Bashar Al-Assad, but also Kurdish fighters.
The recent battle for Kobane, in which IS overran the small northern Syrian town, forcing almost all of its civilians to flee into Turkey, was deadly. Hundreds of IS fighters were killed, and this is in part why the mortality rate is so high, the interior ministry explained.
Around 500 nationals are currently fighting jihad along IS in Syria, and 50 are believed to have died since January. This was the total death toll for the whole of last year, and represents an increase of 280%.
Yet these figures coincide with conflicting reports from experts, who say the government hasn't got a clue when it comes to determining whether a jihadist is dead or not.
They've latched on to the current confusion over the purported death of notorious IS recruiter: Omar Diaby, alias Omar Omsen.
Since last Saturday, rumours have been floating around, claiming that the Franco-Senegalese militant, who was notorious for recruiting hundreds of French nationals through sophisticated propaganda, was killed.
Three days on, the interior minister is yet to confirm. Bernard Cazeneuve, has so far only said that "checks are in progress."
Authorities are being cautious because so many announced deaths have turned out to be false.
Last year, Frenchman David Drugeon, a young convert to Al-Qaeda in Afghanistan and then Syria, was recently pronounced dead in an American drone attack, before it was disproved.
"We just can't confirm the deaths of people out there," Alain Chouet, a former French spy chief, told AFP.
The government also has to be careful not to give potential targets the upper hand by allowing them to lie low.
"Seeing that Islamic State is losing ground militarily, quite a few foreigners, French, British or Chechen want to play dead, to be able to disappear," said Chouet.
The other trap to avoid is martyrdom. Death is the goal for many IS fighters, like it was for Al Qaida. Handing it to them on a plate, may bolster their cause unwittingly.