The officials said Riyadh warned the German authorities the suspected attacker, Taleb al-Abdulmohsen, a Saudi dissident who described himself as an ex-Muslim, had boasted on social media that “something big will happen in Germany”. It was unclear if police ever acted upon the warnings.

The man suspected of driving a car into a Christmas market in Germany is an exiled Saudi doctor who praised far-Right politicians for combating the “Islamisation” of Europe and pledged to take “revenge” for the “harassment” of female refugees.

German police had been repeatedly warned that a Saudi doctor who is suspected of ploughing a car into crowds at a Magdeburg Christmas market posed a terror threat.