South Africa's ruling party backed Finance Minister Pravin Gordhan on Tuesday but said ministers should obey police summons issued during investigations, days after Gordhan declined to meet detectives looking into his time at the tax office.
Gordhan said last week he had done nothing wrong and had no legal obligation to obey a police summons over the probe into whether he used a surveillance unit set up when he was head of the tax service to spy on politicians.
There has been speculation in local media that Gordhan could be charged over the investigation, but state prosecutors have denied the claims, which have hit South African assets.
"The continued speculation and the public spectacle ... is hurting the economy and could be dealt with better," African National Congress (ANC) Secretary General Gwede Mantashe said. "The ANC reaffirms its unreserved confidence in the Minister."
The rand gained briefly after Mantashe expressed confidence in Gordhan but then went into reverse, falling 0.6 percent to a session low, after he told a news conference that ministers must obey police summons.
"The minister must cooperate with processes. If he has no case to answer he can only prove that through processes," Mantashe told a news conference.
He also said the Treasury, one of South Africa's most respected government departments, should not seek to present itself as being above the law and deserving of special treatment.
"We do however caution them against taking a public posture that seems to isolate themselves from the rest of government and positions them as victims to be protected by society," he said.
The investigation first came to light in February. Political analysts say it is part of a plot to undermine Gordhan by a faction allied to President Jacob Zuma, who is said to have been among the politicians spied on by the tax surveillance unit.
Zuma has denied warring with Gordhan.
(Reporting by Stella Mapenzauswa; Writing by James Macharia; Editing by Ed Cropley)