In 2010 former special forces operative Mike Peega leaked a dossier to the media claiming that a rogue spy unit at the South African Revenue Service was targeting politicians and businessmen close to President Jacob Zuma.
Peega's dossier was discredited because he had previously been arrested for rhino poaching and fired from SARS, although the case against him was later withdrawn.
SARS spin doctors and officials rushed to defend their "legal" mandate to infiltrate organised crime syndicates.
Their main targets were cigarette and drug smugglers. Like any other revenue service in the world, SARS had specialised units authorised to use unorthodox methods to go after them.
Peega was treated like a crackpot with an axe to grind, someone who was peddling fabrications for his own obscure ends.
Behind the scenes the State Security Agency investigated the allegations made by Peega and others that SARS was engaged in illegal intelligence-gathering. But SARS's official explanations were broadly accepted as credible and the story died.
It took an ill-fated love affair between SARS head of risk and enforcement Johann van Loggerenberg and Pretoria lawyer Belinda Walter to bring it back to life.
Last year Walter, who spied on tobacco companies for the State Security Agency, lodged a complaint against Van Loggerenberg for allegedly intercepting her phone calls and disclosing confidential taxpayer information.
At the time of their relationship Van Loggerenberg led several investigations into high-profile tax cheats, including Julius Malema and Radovan Krejcir, and tobacco firms that Walter represented.
Walter's complaint prompted Ivan Pillay, who was then acting SARS commissioner, to launch an internal probe. This found Van Loggerenberg guilty of unprofessional conduct but made no definitive adverse findings against him.
Van Loggerenberg claimed Walter was part of a dirty-tricks campaign orchestrated by rogue elements in the police and intelligence services colluding with tobacco kingpins and other criminals he was investigating.
This claim was later investigated by the inspector-general of intelligence, Advocate Faith Radebe, and according to State Security Minister David Mahlobo was found to be baseless.
Next, Pillay appointed an external panel led by Advocate Muzi Sikhakhane to investigate Walter's complaint against Van Loggerenberg.
Halfway through the investigation Zuma appointed Tom Moyane as the new head of SARS.
Soon afterwards the Sunday Times reported the unit had allegedly bugged Zuma's private home in Forest Town, Johannesburg, conducted illegal surveillance on senior ANC leaders ahead of the party's Polokwane conference in 2007, and had run a brothel.
This led to the mandate of the Sikhakhane panel being expanded to look into the rogue unit, and also sparked accusations that Moyane was engaged in a politically motivated witch hunt.
Radebe also conducted a separate investigation that was completed last December but has never been made public.
The Sikhakhane panel handed its findings to Moyane on November 5. It found that there was prima facie evidence that SARS had established a unit that conducted illegal covert intelligence gathering.
This prompted Moyane to institute a slew of disciplinary charges against senior SARS officials, including Pillay and Van Loggerenberg.
A wave of resignations and court challenges bolstered the view that Moyane was orchestrating a politically motivated purge of SARS officials not loyal to Zuma.
According to this view, Pillay and Van Loggerenberg in particular were being victimised by Zuma and the ANC because they had confiscated a consignment of party T-shirts ahead of the 2014 general elections and cracked down on alleged tax infractions by Zuma's son Edward.
Earlier this year Finance Minister Nhlanhla Nene appointed an advisory board led by retired judge Frank Kroon to get to the bottom of the mess at SARS.
This month Kroon found that SARS had indeed broken the law in setting up the rogue unit and that it had committed illegal acts.
"We have satisfied ourselves that the covert unit was an unlawful one, and that its activities were unlawful," Kroon told a news conference.
Kroon also announced that former chief justice Sandile Ngcobo would chair disciplinary hearings against Pillay and SARS head of strategy and risk Peter Richer.
These had been due to start on Friday, but last week SARS issued a terse statement saying it had parted company "amicably" with Pillay and Richer and that all charges and pending investigations against them were summarily dropped.
This bolstered perceptions that the officials were being purged for political reasons.
However, investigations into the rogue unit by audit firm KPMG and an independent counsel are continuing and keep uncovering new evidence of wrongdoing - most recently a memo showing SARS had planted bugs in the NPA's offices to keep tabs on the corruption investigation into former police chief Jackie Selebi.
These revelations have prompted two former rogue agents to confess, and sparked a complaint to the Hawks against former rogue unit commander Andries "Skollie" Janse van Rensburg.