More than 100 French jihadists regularly received welfare payments after joining Isil forces in Syria and Iraq, police have disclosed.

The payments came to light after the launch of an investigation into Islamic State of Iraq and the Levant (Isil) funding in France and other European countries in 2015.

Their discovery highlighted intelligence failings and revealed that social security offices neglected to carry out checks.

The Criminal Brigade in Paris and other European security services unearthed fraudulent welfare payments to jihadists totalling more than €2 million (£1.8 million) from Europe between 2012 and 2016. Some €500,000 came from France.

The other European countries involved were not named. Most European Isil fighters come from France, followed by Germany and Britain.

Detectives said about a fifth of the approximately 700 French nationals they estimated left the country to join the extremists had continued to claim unemployment or housing benefits, income support or family allowances.

About 420 fraudulent welfare payments to French fighters were discovered last year.

An investigator told Le Figaro newspaper: “Relatives used identity papers with photos to claim money from social security offices or family allowances on their behalf and then transferred the funds to them in the combat zones, mainly via Turkey.”