Freedom Under Law (FUL) on Monday rubbished the summons served on former South African Revenue Services (Sars) senior staffers and said the latest move by authorities would not go anywhere.

Last week, former Sars deputy commissioner Ivan Pillay, former head of the High Risk Investigation Unit (HRIU), Johann van Loggerenberg and Andries Janse van Rensburg announced that the Directorate for Priority Crime Investigation (DPCI), known as the Hawks, served them with a summons relating to a report by auditors KPMG regarding a rogue spy unit in the revenue service.

FUL said it was convinced that the charges were "as groundless as those of 2016 and will suffer the same fate".

"FUL notes with concern that, although Ivan Pillay and Johann van Loggerenberg have throughout been able and willing to co-operate, these brand-new charges have been presented without any enquiry, forewarning or opportunity to make representations," the organisation said in a statement.

"This is in such contrast to the courtesies accorded others that there is every reason to question the motive behind these renewed allegations."

When the allegations of the "rogue spy unit" surfaced, it was widely believed it was used in a bid to try and get rid of former Sars commissioner Pravin Gordhan and those loyal to him.

Gordhan was fired from his job as South Africa's finance minister by former president Jacob Zuma in March last year, after the National Prosecuting Authority (NPA) tried to prosecute him on charges related to Pillay being given an early pension. This case was withdrawn due to a lack of evidence.

KPMG's "rogue unit" report was called into question, leading to the auditing firm canning the report and apologising to Gordhan.

FUL said it would write to President Cyril Ramaphosa urging him to consider suspending NPA boss Shaun Abrahams and senior managers, Priority Crimes Litigation Unit  head Dr Torie Pretorius and advocate Sibongile Mzinyathi.