According to prosecutors, the equivalent of $6.5 million in cash was found during a search of his apartment.
Gharibashvili has admitted to receiving illegal income for several years as part of an agreement to reduce his prison sentence.
Gharibashvili served as prime minister for two terms, 2013-2015 and 2021-2024.
Georgia has been in a political crisis since October, when the Georgian Dream party declared itself the winner of the parliamentary elections but was accused of fraud by the opposition.
