Public Protector Thuli Madonsela will conduct a preliminary probe into former crime intelligence boss Richard Mdluli, her office said on Tuesday.

Human Settlements Minister Tokyo Sexwale's legal representatives made a request on May 19 for a probe after a report by Mdluli, alleging that a number of ANC leaders were part of a plot to unseat President Jacob Zuma.

Last year, Mdluli claimed that former president Thabo Mbeki's "camp" was trying to take over crime intelligence ahead of the ANC's elective conference in Mangaung, in the Free State, this December.

Others named in the "Ground Coverage Intelligence Report" included former ANC Youth League president Julius Malema, ANC treasurer general Mathews Phosa, and ANC national executive committee members Fikile Mbalula, Jeff Radebe, Tony Yengeni, Cassel Mathale and David Mabuza.

Madonsela's office said she would speak to the non-profit organisation Freedom Under Law (FUL) as part of the investigation.

On May 15, FUL applied for an urgent interdict to prevent Mdluli from serving in the police service, just six days after Police Minister Nathi Mthethwa announced that Mdluli was being shifted to another division.

On May 27, Mdluli was suspended by acting national police commissioner Nhlanhla Mkhwanazi.

Madonsela's office said she would also ask Intelligence Inspector General Faith Radebe about her probe into claims that Mdluli misappropriated R5-million from a secret intelligence slush fund.

The Democratic Alliance and the FW De Klerk Foundation asked Madonsela to investigate the allegations, which were already under investigation by Radebe at the time.

On April 25, Madonsela said she would wait until Radebe had concluded her work before deciding whether she needed to conduct an investigation.

Last year, Mdluli faced fraud and corruption charges relating to alleged misuse of the fund for the purchase of luxury vehicles, and the hiring of family members.

He also faced a murder charge for the death of his former lover's husband.

All the charges were withdrawn and Mdluli was reinstated in March as head of crime intelligence.