The Gestapo preferred to delegate arrests to regular policemen in order to be themselves less visible to the populace. The officers took Sergey to the police prison on Alexanderplatz, and a few days later the Gestapo transferred him to the "Arbeitserziehungslager (AEL) Wuhlheide," one of the Gestapo's preliminary detention and labor camps (right next to the later East Berlin Zoo). In February or March 1944 he was taken back to the police prison on Alexanderplatz, Station 3 (political prisoners), awaiting the transfer to his final destination which by this time he may not yet have known.
Something had gone on in the meantime. On January 14, 1944, one month after his arrest, the Kripo dutifully noted that "the Stapo had given the order to commit Nabokoff to the Konzentrationslager [KZ] Neuengamme for an indefinite period of time."
Очень интересная статья известного журналиста, переводчика и набоковеда Дитера Э. Циммера о судьбе Сергея Набокова. Превосходная проработка архивного материала, в том числе из сохранившегося в берлинском ландесархиве полицейского досье С.Набокова:
What Happened to Sergey Nabokov
К той маленькой главке, в которой я упоминаюсь, хотел бы добавить, что идея и инициатива розысков исходила от Г.Г.Суперфина.