Businessman Jared Otieno and 15 others have been charged with conspiracy to defraud and obtaining money by false pretence.
Otieno and his co-accused denied the charges on Tuesday before Chief Magistrate Francis Andayi at the Milimani Law Court.
They were charged with fraudulently receiving Sh300 million in a fake gold transaction.
Otieno and his co-accused will remain in custody until May 27, 2019, pending their bail ruling.
Senior principal magistrate Paul Mayova last week allowed an application by the prosecution seeking to detain Otieno longer on grounds that he would interfere with investigations.
The prosecution had made an application seeking to detain the businessman for 14 days, but the magistrate said seven would be sufficient.
The DCI in the application sworn by Felix Banzi said they are investigating Otieno for obtaining money by false pretence.