Abdulmohsen, a Saudi-born psychiatrist, drove into a Christmas market in Magdeburg, killing and injuring many people. Saudi Arabia had warned Germany about him several times, but German authorities did not act.

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.

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.