As former finance minister Pravin Gordhan weighs his legal options concerning action against auditing firm KPMG, several regulatory bodies are also looking into the firm, Business Day reported on Monday.
Last Friday, the firm withdrew the results of its investigation into the so-called Sars "rogue unit" and announced the resignation of eight senior executives, including its CEO Trevor Hoole.
While the firm's internal investigation did not find evidence of illegal activity, it said it should have ceased work for the Gupta family earlier and said the family's companies were often "misleading" and "misrepresenting" facts.
Gordhan said KPMG's apology was not enough and said he was seeking legal advice as to what steps could be taken, if any.
Business Day reported that investigations by the Companies and Intellectual Properties Commission (CIPC) and the Independent Regulatory Body for Auditors (Irba) are underway, while several private firms are looking into their relationship with KPMG.
Investec CEO Stephen Koseff told Business Day that the group would "be considering the report over the next week and will make a call".
"We expect them to conduct themselves in an ethical manner and if they did anything untoward, we would expect them to take action..." he reportedly said.
Irba spokesperson Lorraine van Schalkwyk reportedly welcomed KPMG's decision to publish the findings of its investigation, but reportedly said "the Irba will continue with its own independent investigation in order to bring the case to the necessary conclusion".
The CIPC is investigating possible flouting of the Companies Act by three KPMG partners, who have since been suspended. It is also reportedly investigating the firm's relationship with Gupta companies.