The Tunisian man responsible for the attack on a Berlin Christmas market in December 2016 used a Swiss mobile phone and prepaid SIM card, Swiss and German media sources reported.
The SIM card was not registered in the name of Anis Amri, 24, who ploughed a stolen truck through the Christmas market on December 19, killing 12 people and injuring 56 others. Islamic State later claimed responsibility for the attack, calling the assailant a "soldier" of the militant group.
The Swiss and German news media cited sources described as close to the investigations, which are taking place in several European countries.
The Swiss origin of the mobile phone and SIM card were confirmed by someone who had seen an official document, SRF said. It is not clear exactly how the attacker obtained the mobile phone.
The Office of the Attorney General and the Federal Office of Police told SRF that they could not confirm the information that the media outlets had reported.
There was no information about a SIM card in an already opened criminal investigation into Swiss links with the attack.
“In the framework of the criminal investigation, which was opened based on foreign information, existing contact data around the perpetrator was checked. The investigations have until now not uncovered any concrete evidence of the attacker having likes to people or institutions in Switzerland,” the police and attorney general offices said to SRF.
This echoes earlier statements made by the two offices.
On January 18 Swiss authorities confirmed that the gun used by a Tunisian extremist in the attack on a Christmas market in Berlin last month was brought into Switzerland in the 1990s.
The Office of the Attorney General opened criminal proceedings against “unknown persons” on January 8.
swissinfo.ch and agencies/ilj