Cape Town - National Prosecuting Authority boss Shaun Abrahams said police were still examining a trove of leaked documents detailing relations between the wealthy Gupta family and President Jacob Zuma, but it was too early to say if a prosecution should be launched.
Wednesday's comments to lawmakers by Abrahams were the first time he has spoken publicly about the Gupta case.
"The leaked emails need to be investigated," Abrahams told a parliamentary committee in response to a question on whether his department had taken a position on the matter.
"How can you make a determination on its admissibility if that (police) investigation is still ongoing?", he said.
The elite Hawks police unit, which probes organised and commercial crime and major corruption, is investigating the Gupta allegations, NPA officials told a parliamentary briefing.
Senior ANC members and the opposition accuse the brothers of using their relationship with Zuma to wield influence and win government contracts, allegations that in part stem from a trove of 100 000 documents and emails leaked to reporters.
The Gupta family of Indian-born businessmen were not immediately available for comment on Abraham's remarks.
The brothers, who own a computer business and uranium mine, have previously denied any wrongdoing. Atul Gupta, one of three Gupta brothers, said last month that the emails were fake.
Zuma has also denied any wrongdoing but his relationship with the Guptas has deepened a divide within the ANC ahead of a conference in December where Zuma's successor as party leader - and therefore president - will be chosen.
Zuma survived a no-confidence motion in August. He can remain president until a 2019 election but some opposition politicians have demanded he resign over material in the leaked emails.