Raja Salameh, the brother of the Head of Lebanon's Central Bank, was arrested on Thursday, following his interrogation at a courthouse east of Beirut, Judge Ghada Aoun told Reuters.
Reuters reports that a judicial source separately said that Aoun had charged Salameh with "complicity in illicit enrichment" that also involved his brother, Central Bank Governor, Riad Salameh.
Riad Salameh has not been charged with a crime. He did not immediately respond to a request for comment.
Reuters could not immediately reach legal representatives for his brother for comment.
The source confirmed Raja Salameh had been detained at the Baabda courthouse and remained in custody.