Carabinieri police said they had issued arrest warrants against six suspected jihadis who were "seriously implicated" in the crimes of terrorist association and kidnapping with the aim of terrorism. Police said two of the suspects are already detained in Belgium, while three are at large and a fourth is believed to have been killed.
Three of the suspects were born or raised in Britain and were part of a group known as "the Beatles." They are considered the most violent, police said. Motka and Haines were seized by Islamic State militants in northern Syria on March 12, 2013. Both had been working for the French aid group ACTED at a refugee camp in Atmeh, near Syria's border with Turkey, police said.
Haines was beheaded in September 2014. Police said Motka was freed May 27, 2014. Italy has long been suspected of paying a ransom when its citizens are kidnapped, though the government has never confirmed its methods.
The police statement marked the most detailed information yet provided officially by Italy since Motka's kidnapping and release, suggesting that he had become a key source of information for Italian investigators once he returned home.
Police said their investigation had allowed authorities to form a "complete reconstruction" of the kidnapping as well as the identifications of various detention centers in Syria, which it said could be useful to other European countries as they seek to find still unaccounted-for hostages.
The police statement noted that Motka had been moved 11 times during his detention and had come into contact with "numerous hostages" from Europe and the West. It said the hostages had all been subject to a "harsh regime of detention with episodes of unhuman cruelty."
Police identified the suspects as British-born Aine Leslie Davis and Alexanda Amon Kotey; El Shafee Elskeikh, born in Sudan and raised in Britain; Mehdi Nemmouche of France and detained in Belgium; Soufiane Alilou, born and detained in Belgium; and Salim Benghalem, born in France and believed to have been killed.