"No single person in Sars can decide who to investigate, who to audit, who to settle tax debts with and who not to... There is absolutely no legal basis for Sars to target any taxpayer for political reasons."

It was unfortunate that suspended Congress of SA Trade Unions general secretary Zwelinzima Vavi discussed his tax affairs on social networking platforms, the SA Revenue Service (Sars) said on Wednesday.

"Sars seeks to apply the tax and customs laws it administers with fairness, in a transparent and even-handed manner without any external influence," spokesman Adrian Lackay said.

"No single person in Sars can decide who to investigate, who to audit, who to settle tax debts with and who not to... There is absolutely no legal basis for Sars to target any taxpayer for political reasons."

Lackay was responding after comments made on Twitter over Sars investigating Vavi, saying Sars would not make public comments on Vavi's tax affairs.

A Twitter user suggested that President Jacob Zuma would stick his "dogs Sars" on Vavi if he continued opposing e-tolls in Gauteng.

At 9am on Tuesday, Vavi tweeted: "We not going to buy those etags - we not going to cooperate with privatization of inner city highways without a fight".

Twitter user Aphiwe Mazelem @NangamsoMazelem replied to Vavi at 11.53am saying: "Mr @Zwelinzima1 Vavi, being against #eToll has led to your suspension, #Zuma will send you his dogs, SARS, if you keep on pushing it."

At 12.18pm Vavi replied: "Haha! coincidence - SARS on my case now “@NangamsoMazelem: Mr @Zwelinzima1 Vavi, being against #eToll has led to your suspension".

At around 2.51pm Vavi tweeted: "I pay tax religiously,,every year submit with help of professionals, will organise meeting with SARS, if for some reason I must pay - I will" (sic).

Lackay said it was unfortunate that people turned to social media platforms to speak about their taxes.

"It is unfortunate that high profile public figures in this country use social media platforms to try and conjure up conspiracies about their tax positions," he said.

"Any taxpayer is legally entitled to raise any tax issue directly with SARS at any level of the organisation in order to resolve a tax dispute."

He said there were far more constructive and preferred ways to raise tax issues than making public statements to the media.

Lackay said Sars interacted with more than two million taxpayers every year through various methods of communication.

In August, Cosatu placed Vavi on special leave after he said he had an affair with a colleague.