Two men linked to the deadly terrorist attacks that brought Paris to a standstill on Friday were registered as refugees in Greece earlier this year, Greek authorities confirmed Saturday.

French authorities had asked their Greek counterparts to check a passport and fingerprints of one suspect and the fingerprints of another who were thought to have registered in Greece, which is the main entry point into Europe for Syrian refugees, the Agence France Presse reported.

“We confirm that the (Syrian) passport holder came through the Greek island of Leros on October 3 where he was registered under EU rules,” Nikos Toska, Greek minister for citizen protection, said in a statement, according to AFP.

French police said the passport was found “near the body of one of the attackers” during the investigation into the largest of the Friday attacks, at the Bataclan concert hall, where 82 people were killed.

At least 129 people were killed and 352 injured in a series of shootings and suicide bombings at six locations throughout Paris. Eight attackers were killed, seven of them died in suicide bombings.

The authenticity of the passport, and whether or not it belonged to the attacker, was being check, but the confirmation now indicates a possibly Syrian connection which has been a working hypothesis for investigators.

A Greek police source said the second man had also registered in Greece, reportedly also on Leros in August.

The confirmation has fueled fears that European officials have long held that radical terrorists could infiltrate Europe’s borders along with millions of refugees seeking asylum from Syria’s brutal civil war.