Former Independent Police Investigative Directorate (Ipid) boss Robert McBride has accused ex-police minister Nathi Nhleko of interfering in a law firm investigation that resulted in McBride being suspended and criminally charged in 2015.

Testifying at the state capture inquiry on Friday, McBride claimed Nhleko was willing to "abuse processes to achieve his ends" after he appointed international firm Werksmans to probe what has become known as the "Zimbabwean rendition saga".

McBride and two of his colleagues, Matthew Sesoko and Innocent Khuba, were suspended and charged for defeating the ends of justice in 2015 on allegations relating to the amendment of an internal Ipid report into the illegal deportation of Zimbabwean murder suspects in 2010.

That matter was widely seen as a political manoeuvre to have former Hawks boss Anwa Dramat and his Gauteng commander Shadrack Sibiya removed. Sibiya and Dramat both stood accused of planning and executing an operation that led to the illegal repatriation of five Zimbabweans wanted by that country's police for the murder of a senior officer.

An investigation by Ipid, conducted before McBride's arrival, recommended that the pair be criminally prosecuted on charges of kidnapping and defeating the ends of justice.

But after a review of all the evidence was concluded, McBride ruled differently and submitted a second report absolving Dramat and Sibiya.

McBride went to great lengths on Thursday, the first day of testimony, to explain how he reached that conclusion.

"The minister's office appointed the Werksmans company. At the stage when Werksmans tried to contact Ipid, they attempted to circumvent myself at that stage as the executive director. On two occasions they sent an e-mail with a wrong e-mail address for me, while Sesoko and Khuba's e-mail addresses were correct. My view was that was an attempt to circumvent me," McBride told the commission on Friday.  

"During that period, Khuba got a call from the minister's assistant saying he must speak to Werksmans. That was after I was suspended … Khuba reported having received multiple calls from Nhleko's personal assistant and at some stage Nhleko called Khuba to say he must come to Cape Town.

"When it was reported to me, I noted it was strange and a sign of desperation to somehow prove the lie that was being created, to start a process and put pressure on people. Khuba would later be suspended, disciplined and dismissed on spurious grounds."

McBride slammed the Werksmans' report, saying "they got it wrong and jumped to conclusions".

The report recommended that Dramat and Sibiya be charged with contravening the Immigration Act, kidnapping and defeating the ends of justice; that disciplinary charges should also be instituted against both men; and that McBride, Khuba and Sesoko should be criminally charged for defeating the ends of justice.

"Why wasn't he [Nhleko] just happy to let processes continue? Why would the minister want Khuba specifically to talk to Werksmans?" asked McBride. "He is willing to abuse processes to achieve his ends.

"My view in this instance was that they [Werksmans] got it wrong and jumped to conclusions. It was a hurried report ... This was just a process to ultimately nail us at the end."

The Constitutional Court ruled in 2016 that McBride's suspension was unlawful. Criminal charges against him were dropped soon afterwards.