A 40-year-old Tunisian man who was held on suspicion of being an accomplice of suspected jihadist Berlin truck attacker Anis Amri has been freed, German prosecutors said on Thursday.
Investigations had shown that the unnamed man detained on Wednesday "is not the suspected contact of Anis Amri," said a spokeswoman for the federal prosecution service which handles terrorism cases.
"He has therefore been released from detention," the spokeswoman, Frauke Koehler, told a press conference.
She confirmed that shortly before Tunisian Amri steered a lorry through a Berlin Christmas market in an attack that killed 12 people, he had sent a mobile phone voice message and a picture to a contact -- but said this was not the man who had been detained.
"The investigation into further accomplices or possible people who knew... will continue at full speed," Koehler said.
She also said that a video message released four days after the December 19 rampage, in which Amri is seen swearing allegiance to the head of the Islamic State group, Abu Bakr al-Baghdadi, had been judged authentic.
And the pistol Amri used to fire at an Italian police officer before he was shot dead in Milan last Friday had the same .22 calibre as a bullet that was fired inside the cabin of the lorry.
Investigators were still checking whether it was fired from the same handgun.
The spokeswoman added that the exact cause or time of death of the truck's registered Polish driver, Lukasz Urban, still could not be determined, but that it was "shortly before" the market attack.
The autopsy report was expected in early January, she said, while denying media reports that his corpse bore stab wounds.
Koehler confirmed media reports that the 40-tonne truck came to a rest after 70-80 metres thanks to its automatic braking system that activates when impacts are detected.
This file image grab taken on December 23 from a propaganda video shows suspected jihadist Berlin truck attacker Anis Amri pledging allegiance to the IS.