The South African Revenue Service (Sars) on Thursday said it would investigate allegations of tax evasion before the Zondo commission of inquiry into State capture "without fear or favour".

In a media statement, the revenue service said it was concerned about the allegations that directors of Bosasa, now trading as Global African Operations, had dodged paying tax, using money instead to pay bribes to politicians and government officials to secure lucrative government contracts worth billions of rand.

"Sars is concerned that names of some former employees have been mentioned in alleged wrongdoing and would like to assure the South African taxpayers and public that these will be investigated without fear or favour and guilty persons will be brought to book," the statement said.

"Sars wishes to further assure the taxpayers and public that in instances where tax rules and laws have been violated or undermined, strict measures will be applied to uphold the rule of law."

For the past week, former Bosasa chief operating officer Angelo Agrizzi has, during his testimony before the Zondo commission, been dropping several bombshells, naming names and telling the inquiry that Bosasa executives had also sought to evade paying taxes.

Agrizzi explained the intricate system used by the company to allegedly launder money and pay bribes using a web of fictitious companies, cash cheques and fake invoices in order to win government tenders.

Agrizzi told the Inquiry that Bosasa and its chief accountant were involved in forming small "arms-length companies" with a short lifespan and using them to generate fake invoices.

The invoices paid out by Bosasa would later return to the company's secret vaults as hard cash used to pay bribes.

Bosasa changed to a new system of drawing up dummy employees and issuing cash cheques after the Special Investigation Unit had picked this up. All this was done, Agrizzi said, in order to cheat the tax authorities.