PARIS — The bomb maker for attacks on Paris and Brussels had a previous career as a jailor for the Islamic State group, a lawyer for one of his hostages said Friday.
Belgian authorities say Najim Laachraoui, a 24-year-old Belgian, built the explosive belts used in the assaults on both European capitals and blew himself up at Brussels Airport on March 22. He was also one of several jihadis who held some hostages captured in Syria, according to Marie-Laure Ingouf, who represents former French captives Pierre Torres and Nicolas Henin, both journalists.
"Laachraoui was one of the jailors of the French ex-hostages, and of other decapitated hostages, as they all shared the same cell," she said in a statement.
Her statement, which also referred to beheaded American captives James Foley and Steven Sotloff, said Laachraoui was known at the time as Abou Idriss and worked alongside Mehdi Nemmouche, a Frenchman who is accused of a 2014 attack on the Brussels Jewish Museum.
Didier Francois, a third French journalist also taken hostage, confirmed on Europe 1 radio that Laachraoui was among those responsible for handling the captives.
"He was one of the senior officials in Islamic State, he wasn't a basic guard," he said. "He was responsible for the interrogations. He was extremely subtle. He never used violence like the others."
Nemmouche had already been previously identified as a jihadi jailor. A message left with Nemmouche's lawyer, Sebastien Courtoy, was not immediately returned.
Ingouf's statement partially confirmed a report in the British media identifying Laachraoui as the man who first imprisoned Foley and British photojournalist John Cantlie while Francois' interview corroborated a French report that Laachraoui played a key role during negotiations over the fate of the Frenchman, as well as his compatriots Henin, Torres, and a fourth journalist, Edouard Elias.
All four were eventually released. Foley was beheaded in one of the Islamic State group's first gruesome videos, while Cantlie last appeared in a March IS propaganda video. Cantlie's current whereabouts are not known.
It isn't clear why the Islamic State group had Laachraoui and Nemmouche dealing with hostages. Pieter Van Ostaeyen, who studies the Belgian jihadi networks in Syria and Iraq, said it may simply have come down to language.
"In 2013-2014, it was clearly noticeable that all the French-speaking foreign fighters they grouped together," he said.
Laachraoui, a young mechanical engineering graduate, would have been among the group's earliest recruits, leaving Belgium in February 2013. He returned to Belgium under the alias "Soufiane Kayal."
A central player in the dual attacks that killed a total of 162 people in Brussels and Paris, Laachraoui's job was to make the TATP explosives and the suicide vests used in the assaults. His DNA was found on one of the vests that detonated inside Paris' Bataclan concert hall as well as one that blew up outside France's national stadium on Nov. 13. The last publicly distributed photograph of Laachraoui shows him pushing a cart full of explosives at Brussels' Airport moments before setting them off.
Francois told Europe 1 that Laachraoui was "very intelligent and with a strong belief — which made him even more dangerous."
Lori Hinnant in Paris and John-Thor Dahlburg in Brussels contributed to this report.