Several terrorist suspects were collecting Belgian welfare benefits while plotting attacks in Paris and Brussels, according to investigators.

Belgian authorities concluded that at least five of the suspected conspirators in the Brussels and Paris terrorist attacks were partly financed by the nation’s social-welfare system, receiving in total about $56,000, the Wall Street Journal reported Friday.

Surviving Paris attack suspect Salah Abdeslam collected about $21,000 in unemployment benefits until three weeks before the November assaults. Abdeslam, who was a manager and part owner of a Belgian bar at the time, should have been ineligible for public assistance, officials said.

Numerous suspected terrorists involved in a thwarted Belgian attack had also received welfare benefits, according to a judge who sentenced more than a dozen people who were part of an Islamic State cell to prison last month.

Tom Keatinge, director of the Center for Financial Crime and Security Studies at the Royal United Services Institute in London, said the European benefit system was "vulnerable to abuse for terrorist financing purposes."

Keatinge suggested that European governments offer benefits as vouchers or take a closer look at how people are spending their benefits.

"If you’re paying benefit to people in certain parts of Brussels, maybe you need to be a little more observant about who you’re paying to, and what they might be doing with it," he told the Wall Street Journal.

The Paris and Brussels terrorist suspects who collected welfare were citizens of the European Union. Current Belgian law prohibits benefits from being suspended until an individual is convicted of terrorism or the suspect leaves the country.

ISIS issued a 2015 manual called "How to Survive in the West: A Mujahid Guide" that included a section advising jihadists,"If you can claim extra benefits from a government, then do so."

While Belgium, France, Netherlands, and Denmark have collectively severed hundreds of people from welfare who traveled to Syria to fight with ISIS, European countries have struggled to find a longstanding solution because of generous social-welfare systems.

One Belgian official told the Wall Street Journal that authorities have launched investigations into benefit collections more frequently since the Brussels airport and train attacks in March that killed 35 people. In April, the National Employment Office found that 14 terrorist detainees had received welfare while in prison.

Fred Cauderlier, the Belgian prime minister’s spokesman, defended the nation’s welfare system.

"This is a democracy," he told the Wall Street Journal. "We have no tools to check how people spend their benefits."