What happened to Schmuel father in the boy striped pajamas?

In John Boyne's novel "The Boy in the Striped Pajamas," Schmuel's father, a Jewish watchmaker, was taken away by the Nazis during the Holocaust. The exact details of what happened to him are not explicitly mentioned in the book. However, it can be inferred from Schmuel's experience and the historical setting of the novel that his father was likely imprisoned or sent to a concentration camp.