Prosecutors have charged him with bribery and embezzlement, among other things.
Jun is the first high-profile official in the Moon administration to face a corruption probe. He resigned over the scandal last week but flatly denied any wrongdoing.
Two former aides to Jun and a broker were arrested on bribery charges earlier this month.
Prosecutors said they will consider whether to seek a further arrest warrant against Jun.
Source: Yonhap News Agency