The stimulus package amounts to some 10% of the country's GDP. A total of R130 billion of the package would be supported by reprioritising funds from South Africa's existing budget, News24 reported earlier.
"Regarding conduct failure and in addition to the previously reported investigations into alleged maladministration and irregularities on the procurement process relating to the R37 million Beitbridge Border Post Fence and the R30 million Gauteng e-Government Information Technology tender, Adv Mkhwebane's office is looking into several other matters."
READ | Covid-19 tender corruption 'a major blow for healthcare workers'
The office is also investigating alleged tender irregularities in the awarding of a quarantine camp tender in Mpumalanga.
This comes after allegations that the Zithabeseni facility, which was awarded the contract, is dilapidated and a health hazard for people under quarantine at the premises.
"The complainant further alleged that there has been no provision for necessities such as food and toilet papers at the facility."
In KwaZulu-Natal, Mkhwebane's office is investigating allegations of irregularities in the procurement of personal protective equipment by the provincial Department of Education following allegations that the department procured the PPE at inflated prices.
Meanwhile, in the Eastern Cape, the office is looking into allegations that a lodge used as a quarantine site for Covid-19 is owned by a member of the executive council.
"There is also the case of alleged irregularities in respect of the R400 million e-learning equipment (tablets) tender."
The office said it had also undertaken, at own initiative, to probe allegations of maladministration, improper conduct and the misappropriation of public funds by the Eastern Cape Department of Health in relation to the medical scooters project.
"We have been consistent in our call on the bureaucracy to exercise prudence when it comes to spending public funds on Covid-19 related goods and services. We have stressed that deviation from normal procurement processes is not a declaration of an open season to pillage. We are looking at a few other matters in which we may launch own-initiative investigations," Mkhwebane said.
Mkhwebane said she planned to meet with Social Development Minister Lindiwe Zulu about the special social relief of distress grant grievances, with a "view to finding a speedy resolution to the complaints received".