President Jacob Zuma needs to step up the fight against corruption, the Council for the Advancement of the SA Constitution (Casac) said on Monday.

"Casac has noted the president's affirmation of the government's commitment to the fight against corruption in his address to media owners on [Friday]," Casac spokeswoman Masutane Modjadji said in a statement.

"The recognition that corruption undermines the government's ability to deliver on its mandate to the people of South Africa is a rallying call to steadfastly combat it.

"Whilst acknowledging the efforts that are being made to investigate and prosecute those engaging in these activities we believe that much more still needs to be done to turn the tide against this scourge," said Modjadji.

Casac was "looking forward" to Zuma's formal response to reports by Public Protector Thuli Madonsela that accused national police chief General Bheki Cele and Public Works Minister Gwen Mahlangu-Nkabinde of acting unlawfully in the signing of lease agreements with businessman Roux Shabangu.

The Democratic Alliance has brought criminal charges against the three and Public Works Director General Siviwe Dongwana, for failing to report them to the Treasury.

Modjadji said: "It is unfortunate that criminal charges relating to aspects of the report have been filed before the President has pronounced on the matter."

Madonsela's reports related to Shabangu's lease agreements for police headquarters in both Durban and Pretoria. The Durban lease would have been worth R1.16 billion over 10 years, and that of the Middestad Building in Pretoria R604 million, over the same period.

The Sunday Times reported at the weekend that Zuma had accepted the Protector's findings on the two leases and her recommendation of remedial action, but he has not yet taken any action.

Zuma told journalists last week that he would submit a report on the matter to the Speaker of Parliament on Friday.