Saudi Arabia had previously requested extradition for the Saudi suspect in Germany's deadly Christmas market attack, a source close to the government told AFP on Monday.

"There was (an extradition) request," said the source, without giving the reason for the request, adding that Riyadh had warned the suspect "could be dangerous".

Five people were killed and scores were injured when Taleb al-Abdulmohsen drove an SUV at high speed through a dense crowd in the eastern city of Magdeburg Friday.

Media had previously reported that he held strongly anti-Islam views and was angry with Germany's migrant and asylum policy.  

Germany has been hit by multiple deadly jihadist attacks, but evidence gathered by investigators and his past online posts painted a different picture of Abdulmohsen, a 50-year-old doctor of psychiatry.

In an unpublished interview with AFP from 2022 for an unrelated story, Abdulmohsen presented himself as "a Saudi atheist".

He helped Saudi women flee their country -- but also railed against what he saw as Germany's permissive attitude towards refugees from other mainly Muslim countries.

Interior Minister Nancy Fraser said he held "Islamophobic" views. And a prosecutor said that "the background to the crime... could have been disgruntlement with the way Saudi Arabian refugees are treated in Germany".

Taha Al-Hajji of the Berlin-based European Saudi Organisation for Human Rights told AFP Abdulmohsen was "a psychologically disturbed person with an exaggerated sense of self-importance".

In his online posts, Abdulmohsen spoke about his troubles with and suspicions of German authorities.

Last August, he posted on social media: "Is there a path to justice in Germany without blowing up a German embassy or randomly slaughtering German citizens?... If anyone knows it, please let me know."

Die Welt daily reported, citing security sources, that German state and federal police had carried out a "risk assessment" on him last year but concluded that he posed "no specific danger".