Nicqui Galaktiou says authorities have confirmed the existence of the order to her following months of investigation of Malema for corruption charges.
South African officials have declined comment on the matter.
A one-time close ally of President Jacob Zuma, the 31-year-old Malema is now a fierce critic of the government and has strongly denied allegations he profited from government contracts in his home province of Limpopo. Malema led the youth wing of the ruling African National Congress before being expelled this past April for sowing divisions within the party.
Orders for his arrest will likely not play over well with large numbers of South African youth, Malema’s staunchest supporters who are sure to see the move as nothing more than a political witch hunt by the ANC.
According to the weekly City Press newspaper, Malema will be charged with fraud, corruption and money-laundering.
Galaktiou told Reuters that Malema would appear in court next week, but would not be jailed or arrested before then.
“We don’t have a confirmed date yet. We have not seen the warrant of arrest. We don’t know what the charges are,” she said.
Malema told the BBC on Friday that he was not aware of the reported charges and was trying to find out if the warrant had been issued.
He has called for a national mining strike and accused Zuma of ignoring the plight of poor black South Africans.
On Monday, Malema was banned by police from addressing striking workers from the Marikana mine. The miners agreed to a pay offer the next day and have returned to work.
“Not even the president can stop me,” Malema said this week. “Not even death can stop me. My ideas are out there. Even if I am no more, people will continue those ideas.”
The ANC will next meet in December to decide whether Zuma will remain as its party leader going into elections due in 2014.
Malema and others are campaigning for a replacement.