 He was first sent to the camp at Westerbork, then to Villa Bouchina with his wife and three children.For a period of a few months in 1943 they were protected from transport to German concentration camps, supposedly due to the influence of the leader of the pro-German Nationaal Socialistische Beweging, Anton Mussert.On 21 April 1943 Spier was transferred to the Theresienstadt concentration camp, where he was held with his family until the end of the war.