Forensic investigator Paul O'Sullivan will be back in the Kempton Park Magistrate's Court on Thursday for alleged immigration offences.
O'Sullivan had used his Irish passport to leave the country.
He was taken off a plane at OR Tambo International Airport in April 2016 and arrested in front of his two daughters. He was accompanying them back to school in England.
He was charged with Contravening Section 26B of the South African Citizen Act because he left the country on two previous occasions using his Irish passport. The act makes it a criminal offence for a South African citizen to enter or leave South Africa on a foreign passport.
He pleaded not guilty to all the charges.
O'Sullivan said at the time that he used his Irish passport because his life was in danger. He said Czech criminal Radovan Krejcir, who he had been investigating for years, had ordered hits on his life.
Before his arrest, O'Sullivan had sent numerous e-mails to police, threatening to expose alleged corrupt activities by President Jacob Zuma and top police officials.
He goaded them with the words, "stop me if you can", The Star reported.
O'Sullivan said in one e-mail that he would hold a media conference in London to expose the alleged corruption. A 15-member Hawks team arrested him before he could do so.