Former Mozambican finance minister Manuel Chang has been denied bail by the Kempton Park Magistrate's Court.
Magistrate Sagra Subroyen said that releasing Chang on bail would undermine SA's criminal system.
Chang was detained at OR Tambo International Airport on December 29, 2018, while he was making his way to Dubai.
The former finance minister will now have to wait to hear whether he will be extradited to the US when he returns to court on February 26.
The US had asked SA to provisionally arrest Chang over his alleged involvement in financial crimes totalling $2bn (R27.8bn).
The US also accuses Chang of conspiracy to commit wire and securities fraud and conspiracy to commit money laundering during his tenure as minister of finance between 2005 and 2015.
The NPA had argued that Chang was a flight risk, and would flee to his home country should he be granted bail.
The magistrate said Chang failed to prove beyond reasonable doubt that he was a suitable candidate for bail.
Chang failed to disclose his finances
Subroyen went on to state that Chang failed to disclose his finances to the court, despite serious accusations being levelled against him.
"He failed to disclose his financial records, and told the court that he only earns $9 000. But it was later found by the court, that in fact Chang has various other accounts with cash reserves in them, and believe there could be more," Subroyen added.
The magistrate also said there was some months where there was no movement in Chang's bank accounts, and questioned "how he went about his living".
She added that she noted arguments raised by Chang, including the conditions of his detention, his health and dietary requirements.
"The applicant submitted that he has high cholesterol and is diabetic. However [he] did not provide any proof of his medical condition," said Subroyen.
"The Mozambican constitution protects its citizens from extradition, and should the applicant flee the country (SA), he may not be extradited to the US to face his charges," continued Subroyen.
The former minister argued, during his bail hearing, that his detention was unlawful and that his extradition, if carried out, would also be illegal.
Subroyen said that the hearing was in line with South African Constitution, and ordered that the hearing continue to be heard under a schedule 5 offence.
"The applicant is a person of influence, and may very well have his way in returning to his home country, despite his travel documents being handed in to relevant officials," said Subroyen.
"He may be tempted to flee".
Chang also submitted that he would not afford the R200 000 bail, saying that it may exhaust his savings.
But Subroyen said that the former minister failed to make his financial standings available to court for consideration, and also took note of the luxurious trip to Dubai during which Chang was detained.
"Seemingly for his protection, the applicant played his cards close to his chest, and could have said more to exonerate himself."
Meanwhile, Mozambique has also requested that the ex-finance minister be extradited.
Five officials, linked to Chang's alleged crimes, were recently arrested in Mozambique.
Among those arrested are Gregorio Leao, ex-director of the intelligence services, and Ines Moiane, a former assistant of former president Armando Guebuza.
AFP on Thursday reported that businessman Teofilo Nhangumele, accused of introducing secret service officials to a company which went on to sell surveillance ships and a tuna-fishing fleet to the government, was also detained.
The group is alleged to have been part of a scheme who benefited from loans from the USA, which never made it to the country's coffers, plunging it into a financial crisis.