Berlin: Germany’s Interior Ministry says it will “leave no stone unturned” in trying to determine how a Bundeswehr soldier who spoke no Arabic managed to register as a Syrian asylum seeker.

Conceding that mistakes were made, spokesman Tobias Plate said on Friday every effort was being made uncover how Franco A. duped authorities and was given a place in a refugee home and collected financial aid.

The 28-year-old lieutenant was arrested on Wednesday and charged with preparing an act of violence that he’s suspected of planning to blame on refugees.

He allegedly stashed a pistol in a Vienna airport bathroom and was taken into custody when he went to retrieve it in February. He was freed but Austrian authorities informed Germany, and a fingerprint match showed he’d registered as a refugee.

Meanwhile, Italian police said on Friday they had helped their German counterparts neutralise a Berlin-based Islamist terror cell with links to Christmas market attack suspect Anis Amri.

The dismantling of the 11-strong group was completed at the end of January after nearly two months of investigations triggered by two of them being picked up at the Italian port of Ancona on December 4, 2016, according to the antiterrorism wing of Italy’s state police force.

Italian authorities believe Congolese national Lutumba Nkanga, 26, and Moroccan Soufiane Amri, 22, were planning to travel to Istanbul en route to joining Daesh in Iraq or Syria.

Their departure was delayed by a Greek ferry strike and it was during the unexpected delay that they were subject to an identity check which revealed that Germany had banned Soufiane Amri from leaving the country.

Amri was deported to Germany while Nkanga was detained in a centre for failed asylum seekers awaiting deportation in the southeastern port of Brindisi.

Subsequent investigations and monitoring of Nkanga’s telephone calls from the centre established that the two men had been travelling with false documents and were in regular contact with other members of the cell based in the central Berlin district of Moabit.

Three other members of the group were arrested on December 4 at Bajakovo at the border between Croatia and Serbia, the Italian police said. Emrah Civelek, Feysel Hermann and Husan Saed Hussain were also said to have been trying to get to Iraq or Syria.

Civelek was described as a Berlin taxi driver who was involved in the running of the “Fussilet 33” mosque, which was closed down in February because of concerns it was a meeting place for Islamists.

Several members of the Berlin group had contact with Anis Amri and the suspected marketplace attacker was a regular visitor to lodgings shared by Soufiane Amri and Nkanga, according to the Italian police.

A Tunisian national unrelated to his Moroccan namesake, Anis Amri was shot dead by Italian police in Milan on December 23, four days after the market attack claimed by Daesh left 12 people dead.

German police did not immediately respond to requests for details of the operation against the Berlin cell which the Italians described as “a very diverse group of militants.”