Rome: Tunisian suspect Anis Amri smuggled the weapon used in the Berlin Christmas market attack across borders to Italy and used it in the shoot-out in which he was killed, police said on Wednesday.

Italian police said ballistic tests proved the gun fired at an officer in Milan was the same as the one used to kill the Polish driver of the hijacked truck which Amri is believed to have ploughed into the crowd on December 19, killing 12.

“The weapon that killed the driver of the Berlin massacre truck is the same as the one Anis Amri used to wound a policeman in Milan,” forensic police said in a statement.

An investigation was underway to see whether the weapon had been used “in other criminal episodes, in Italy or elsewhere”.

Amri, 24, the prime suspect in the Berlin Christmas market attack, was shot dead after travelling from the Netherlands to France before heading to Italy.

The Tunisian was approached by two policemen as he loitered outside a Milan train station. He fired at one officer before being shot dead by the other.