Belarusian Security Council Secretary Leanid Maltsau told journalists in Minsk on November 9 that the decision was made after a special gathering of the country's top security officials.
President Lukashenka, Prosecutor General Alyaksandr Koniuk, and Investigative Committee chairman Valeri Vakulchik questioned the KGB's top officials regarding "the latest developments in the KGB ranks, including the recent suicide of KGB Colonel Alyaksandr Kazak."
Maltsau said he will be the KGB's acting chairman while investigations of KGB operations are in progress.
Maltsau, however, indicated that Zaytsau may only be temporarily suspended from his post until the investigation into Kazak's alleged suicide is completed.
If the investigation shows that he is in the clear, "there is no doubt that he will return to office," Maltsev told the RIA Novosti agency.
Kazak, 47, was found dead of a gunshot wound in a forest in October. His death was ruled a suicide but some believe he was killed.