An assailant has stabbed the son of former German president Richard von Weizsaecker to death in an attack at a hospital in Berlin. The attack also left one other person seriously injured.

The German Police on Wednesday said that the motive for the attack on the 59-year-old  Fritz von Weizsaecker on Tuesday evening was unclear.

Von Weizsaecker, a doctor had just delivered a lecture on liver diseases at the Schlosspark hospital in the western Berlin neighbourhood of Charlottenburg when he was stabbed. He died at the scene despite efforts to save him.

The suspect was overpowered by other people present, one of whom was severely injured by the attacker.

Police has however opened an investigation into the incident and were expected to release information about the assailant and his possible motive for the attack on Von Weizsaecker, who was married with four children.

His father, Richard von Weizsaecker who died in 2015 was considered one of Germany’s great post-war political figures. He was president of West Germany from 1984 to 1990 and then held the same position in the united Germany from 1990 to 1994.

He was previously a deputy in the lower house of parliament for the CDU now led by Chancellor Angela Merkel. He was once a mayor of West Berlin.