There are conflicting reports over the identity of the suspect in the Berlin truck attack that killed 12 people at a busy Christmas market in the city.

German Interior Minister Thomas de Maiziere said the suspect came from Pakistan and had applied for asylum in Germany,.

According to the police they detained a man who could not have been the actual perpetrator.

While, the arrested man has denied any involvement in the attack.

As per the reports, He had entered Germany on December 31 last year and arrived in Berlin in February.

Meanwhile, Die Welt newspaper reported, German police believe the man from Pakistan was not the the actual perpetrator, citing senior security sources.

The arrest of an asylum-seeker came as a shock as Germany is one of the few European nations to open its borders for migrants from war-torn West Asia.

"I know that it would be particularly hard for us all to bear if it were confirmed that a person committed this act who asked for protection and asylum in Germany," German Chancellor Angela Merkel said. "This would be particularly sickening for the many, many Germans who work to help refugees every day and for the many people who really need our help and are making an effort to integrate in our country."

German Chancellor Angela Merkel described herself as "shocked, shaken and deeply saddened" after what she said the government must assume was a "terrorist attack." Mr. De Maiziere said that as far as officials know, the Islamic State group has not claimed responsibility.

Authorities arrested a man about 2 kilometres from the crash site on suspicion of having been at the wheel of the truck. Footage showed the suspect, his head covered in a white sheet, being pushed into a police car shortly after the attack. Berlin's Tagesspiegel newspaper reported that the man was known to police for minor crimes.

Watch the video here: