Berlin police defended themselves on Friday against accusations that they stopped surveillance on Berlin Christmas market attacker despite knowing in June 2016 he was dangerous.
Anis Amri, who had sought but been denied asylum in Germany, drove a truck into a Berlin Christmas market on December 19, killing 12 people and injuring dozens.
The Tunisian national had been under surveillance for months by Germany's domestic intelligence agency, which deemed him willing and able to commit a terrorist attack at any time.
On Friday, police in Berlin told a state-level committee that the Office of Criminal Investigation requested an extension of the surveillance on Amri from the judicial authorities on June 30 and August 19, 2016.
The requests had been based on potential risks, they said.
The surveillance that had been carried out in advance of those requests had yielded no results, so it was suspended on June 15, 2016, they added.
The police wanted nonetheless to tap Amri's conversations and messages, above all to keep track of him and to gather further evidence.
The Berlin-Brandenburg Radio (RBB) station reported earlier that while Amri's surveillance had been ended mid-June 2016, he was still considered a person with a high potential to commit violence and a security risk.