"The investigation is complete. All we are doing now is tying [up] the loose ends."
The possibility that Zuma could face trial upstaged his first public speech since he defeated Thabo Mbeki, South Africa's president, in a bitter African National Congress (ANC) leadership contest on Tuesday.
At a news conference, Zuma complained he was being tried in the media.
"There was an investigation which was conducted publicly against me, I was threatened to be charged in public, there were things said about me by those investigating," he said.
"My problem was, why are these things being said in public? If I have a case to answer, then take me to court."
Michael Hulley, Zuma's lawyer, was reported by the Reuters news agency as saying Mpshe had not notified him about possible legal action.
"I can only speculate that the actions of the national director are fuelling and lending credence to the idea that state resources are being used against my client," he said.
Speaking to Al Jazeera, Steven Friedman from the Institute for Democracy, stressed that Zuma had not yet been charged, but said that if charges were brought, a number of possibilities could be expected - including angry reactions from supporters demanding that the charges be dropped.
Though popular among the ANC's grassroots supporters, Zuma has been dogged by scandals in the recent past.
Mpshe is investigating allegations that in the 1990s, Zuma accepted hundreds of thousands of dollars in bribes from the French company Thint to stop investigations into a multibillion-dollar arms deal with the government that was suspected of being secured through bribes.
Zuma denies the charges and says prosecutors are trying to smear his name for political reasons.
Schabir Shaik, Zuma's financial adviser, is currently serving a 15-year prison sentence after he was found guilty of soliciting bribes on behalf of the new ANC leader.
Mbeki fired Zuma in 2005 after he was charged with bribery and fraud over the arms deal scandal.
But the charges against Zuma were thrown out
in 2006 after a high court judge ruled documents obtained during raids on Zuma's home could not be used by prosecutors because the warrants used to obtain them were illegal.
Then last month the Supreme Court said the warrants had proper legal authority, clearing the way for the evidence to be used in any future corruption trial against Zuma.
Elite police unit
Days before Zuma became ANC leader, an elite police unit called the Scorpions filed papers in the Constitutional Court containing what they said was new evidence against him.
Zuma denies any wrongdoing and his supporters say he is the victim of a plot by Mbeki who has been left without office in the ANC after Zuma won the vote to lead the party.
Kalay Maistry, Al Jazeera's correspondent, said the future of the Scorpions Unit which put together the case against Zuma is now under question, with party delegates expected to take a decision on the future of the unit.
Maistry reported that the ANC appeared even more divided than it was before the leadership race.
Zuma's reputation has also been tainted by a sex scandal. An HIV-positive woman accused him of rape, though the courts later absolved Zuma of the charge.
Zuma was elected head of the ruling African National Congress on Tuesday, defeating Thabo Mbeki, the South African president.
Despite the leadership battle, in his first speech as party leader on Thursday, Zuma paid tribute to Mbeki, calling him "a comrade, friend and brother".
He said there was "likely to be anxiety regarding the existence of two presidents, one of state and the other of the party" but promised there was "no reason for uncertainty or fear".
"The conference is now behind us and we will continue to work together to unite and build a stronger ANC," he said.
Zuma promised continuity in ANC policies, which have seen the longest period of growth in South Africa's history.
During his campaign for the party leadership, Zuma had challenged Mbeki's muted approach to confrontation with neighbouring Zimbabwe, where Robert Mugabe, Zimbabwe's president, is accused of ruining the economy.
But Zuma was conciliatory on that point on Thursday, saying he was "confident" in the "quiet diplomacy" approach and promised "we are going to continue with it".
As the ANC's head, Zuma is favoured to become the country's next president when Mbeki steps aside in 2009, though a conviction for corruption would force him to stand down.