It finds he acted unlawfully by meddling in the affairs of the administrative authority of the Health Department.
President Cyril Ramaphosa released the report on Wednesday.
The evidence obtained suggests Dr Anban Pillay, as acting Health Department DG, should be criminally prosecuted for financial misconduct.
Evidence also shows Mkhize's associates committed fraud.
Charges of fraud and embezzlement against Tahera Mather and Naadhira Mitha were laid in May.
The report shows the two failed to tell the Health Department that Digital Vibes was also tendering for the NHI media campaign contract.