South African police are investigating President Jacob Zuma over a $23 million taxpayer-funded refurbishment at his rural homestead, according to parliamentary papers.

In a written response to lawmakers published yesterday, police confirmed that an investigation into spending at the property "has been initiated".

Zuma, who was reelected in May, has insisted that he had no knowledge of the work, including the construction of a swimming pool, private clinic and amphitheatre.

His government insists

all the refurbishments at the homestead in Nkandla in the southeastern province of KwaZulu Natal were security related.

The issue has become a lightning rod for criticism of Zuma's administration, which is seen by many South Africans as tolerant of corruption and incompetence.

Opposition leader Mmusi Maimane of the Democratic Alliance laid the corruption charges againstZuma in March.

The move came after public ombudsman Thuli Madonsela ruled that Zuma had "benefited unduly" from the construction, ordering him to pay part of the cost.

At the time, Maimane said: "There can be no doubt that this Nkandla palace was built on corruption by the president for the president with our money."

He and other opposition politicians have repeatedly called for Zuma to resign.

Yesterday's confirmation of the investigation

came with few details.

"The investigation in this regard has been initiated and no further information can be disclosed at this juncture as the matter is still sub judice," Police Minister Nathi Nhleko said in a written statement to parliament

The president's spokesman refused to comment.