"Having concluded the forensic investigation... [the] report confirms that there is prima facie evidence of irregular awarding of contracts," mayoral committee member Matshidiso Mfikoe said in a statement on Friday.

The investigation was carried out by the Joburg Risk and Audit Service and Ernst & Young.

According to the statement, the report found some contracts awarded by Pikitup were in contravention of prescribed legislation, policies and procedures.

It also implicated a number of employees and board members.

Pikitup is a municipal entity mandated to provide waste management services in the greater Johannesburg area.

The company's interim board appointed Ernst & Young in June last year to conduct an in-depth forensic audit into allegations of corruption. This came after the resignation of nine members of its previous board.

Mfikoe said: "The main objective of [the audit] was to establish whether the awarding of tenders and the extension of contracts to service providers during the tenure of the previous board was in accordance with the provisions of the Municipal Finance Management Act."

Ernst & Young had found that several high-ranking officials had "misused" their position to influence the awarding of tenders and the extension of contracts.

"Such activities have exposed Pikitup to risks of corruption, and may have been motivated by personal interests," Mfikoe said.

The report had identified irregularities and appointments in relation to the fleet and waste collection service, street cleaning, internal technology solutions, refuse removal and ancillary service, and the operation and maintenance of plants and equipment.

It recommended that current managing director Amanda Nair take action, which might include suspension and disciplinary processes.

Pikitup was conducting further investigations, Mfikoe said.