Transnet Freight Rail breached regulations when it procured goods and services from consulting companies, according to a newspaper report on Wednesday.
A forensic report compiled by auditors Nkonki found that the transgressions went unpunished costing the company millions, the Sowetan newspaper reported.
The report revealed that senior group executives had been involved in wrongdoing when appointing consulting companies.
It concurred with Transnet Freight Rails' chief executive Siyabonga Gama that he was selectively disciplined.
Gama was suspended and later dismissed for breaching tender regulations. In February last year, he was reinstated.
The forensic report was commissioned by Transnet late last year following Public Protector Thuli Madonsela's inquiry on procurement irregularities at the company.
The parastatal's board was scheduled to discuss the report next week.