Opposition lawmakers have called for Bilel Ben Ammar to be questioned as part of a parliamentary probe into the attack, amid concerns that authorities failed to properly investigate the man's possible involvement.
Amri, a Tunisian like Ben Ammar, drove a stolen truck into a busy Christmas market on Dec. 19, 2016, killing 12 people, before fleeing the scene. He was killed days later in a shootout with police in Italy.
German media reported last week that Ben Ammar had ties to Moroccan intelligence and may have been at the Christmas market shortly after the attack. Germany's interior minister, Horst Seehofer, said there was no evidence for either claim.
Presenting a 13-page report on Ben Ammar to reporters in Berlin, Seehofer said his office had reviewed the circumstances of Ben Ammar's deportation and concluded that authorities had acted according to the law. The government earlier strongly denied suggestions the deportation had been part of an attempted cover-up.
Citing lack of evidence tying Ben Ammar to the attack and his known extremist views, Seehofer said it was "thoroughly understandable" that authorities at the time had decided to expedite the man's deportation to Tunisia, which occurred on Feb. 1, 2017.
Seehofer said he didn't know Ben Ammar's current whereabouts and couldn't rule out that the Tunisian might have returned to Germany again. Asked about a picture on Ben Ammar's phone showing a boarding pass for a flight from Berlin to Nice, Seehofer declined to comment, citing ongoing investigations into the July 14, 2016, truck attack in the French city in which 86 people were killed. The name on the boarding pass doesn't correspond to one of the 12 aliases Ben Ammar used, according to German authorities. Separate pictures show Ben Ammar in Paris the same month.
The phone also included pictures Ben Ammar took of the site of the Christmas market attack months before it occurred, as well as images sent to him via social media after the attack.