Suspended Public Protector Busisiwe Mkhwebane's latest report on former South African Revenue Service (SARS) official Ivan Pillay – who last week lambasted her investigations into SARS – has been invalidated "by agreement" with her office.

The Gauteng High Court in Pretoria on Monday ordered that the report, which centred on an 18-year-old IT contract, "is reviewed, declared unlawful and set aside" in each instance where it related to Pillay.

More damagingly for Mkhwebane, whose impeachment inquiry continues on Wednesday, the high court also found that the beleaguered Public Protector acted "in breach" of Pillay's constitutional rights by failing to provide him with:

• "any notice whatsoever of the investigation;
• "any of the rights to which he is entitled to in terms of section 7(9) of the Public Protector Act, 23 of 1994; and
• "any right to be heard on the remedial action that the first respondent contemplated granting against him."

Given that Mkhwebane has routinely been lambasted by the courts for failing to afford the subjects of her most barbed investigations – including President Cyril Ramaphosa and Public Enterprises Minister Pravin Gordhan - these same rights, the high court's ruling is very likely to be part of the arsenal of evidence that she needs to address when she testifies at her impeachment inquiry.

In her now partially invalidated report on the SARS' IT contract, Mkhwebane recommended that the Hawks consider investigating alleged criminal conduct by current and former SARS bosses, including Edward Kieswetter and Gordhan.

She released that report on SARS' 2006 contract with software firm Budge, Barone & Dominick (BBD) less than three hours after the State Capture Inquiry found in its latest report that Gordhan was instrumental in resisting the Guptas' takeover of Treasury.

The complaint of "maladministration, improper conduct and procurement irregularities" which prompted the probe, had been launched by former government spokesperson, and current Jacob Zuma Foundation frontman, Mzwanele Manyi, in 2016.

While SARS had used a specific Treasury regulation, which provides for deviation from normal procurement processes without the need to put it out to tender, Mkhwebane said she "could not find compelling reasons for them to do so".

The Public Protector Act also says that the Public Protector should not consider any complaint unless its reported within two years of the incident, barring special circumstances. Mkhwebane, in this case, said she was deviating from the two-year rule because of "special circumstances".

While the Office of the Public Protector has yet to comment on the high court’s ruling, Pillay's lawyers have released a statement, in which they noted that Mkhwebane's latest SARS report was the third in which she made adverse findings against Pillay.

Both of the other two Public Protector reports that made findings against Pillay – including the so-called SARS "Rogue Unit" report and the report on his early retirement – have been overturned by the courts.

"Testifying as a witness on Friday, in the proceedings of the Section 194 Parliamentary inquiry into the fitness of advocate Busisiwe Mkhwebane to hold office, Mr. Pillay highlighted a litany of similar abuses of power in these investigations conducted by the Public Protector against him," his lawyers said.