Allegations of payments for services not rendered and irregular appointments of companies tipped off the initial corruption investigations into Zandile Gumede and her co-accused.

This was the testimony of a senior investigator and assessor in the eThekwini City Integrity and Investigations Unit (CIIU) Shawn Hittler.

Hittler was one of the key officials initially involved in pushing through the investigation against Gumede and others that has led to charges of fraud, money laundering, racketeering and corruption.

He took the witness stand on Friday after his boss, CIIU head Mbuso Ngcobo fell ill and had to be booked off sick until next Wednesday.

Answering questions by senior prosecutor Ashika Lucken, Hittler went through the process of initially capturing the complaint against Gumede.

The court previously heard that an anonymous person dropped a bundle of documents at the CIIU reception area, which triggered a larger investigation.

Hittler said that because the individual was anonymous, they could not be interviewed for further clarity on the alleged corruption.

This was however normal, he said, as there were various anonymous tip-off mediums for the public and City staff.

The bundle of documents did contain a post-it note, he added, stating the allegations in the bundle related to the irregular appointment of service providers, and service providers being paid without rendering services.

In resolving to investigate the matter, Hittler said the bundle of information showed a discrepancy in timelines.

He said one document showed the contract would run for three months, while another indicated six months.

"The disparity regarding the timeframes [was a mitigating factor], but moreover, you have a situation where a complainant says a contract has been irregularly appointed. The only way to take that further is to investigate the matter. Payments were made for services not rendered."

Hittler said that once all the internal processes were completed, they realised that a company implicated in the Gumede investigation was also part of a previous investigation the CIIU undertook.

He said, "That led to the decision to outsource the investigation. We also looked at the capacity of CIIU. We recommended to CIIU head Mbuso Ngcobo to outsource the matter to Integrity Forensic Solutions (IFS)."

Hittler said that they had recommended IFS, from 17 service providers available, because they previously investigated the company linked to an earlier investigation.

"We felt it would help in terms of continuity."

The State is alleging that Gumede, former councillor Mondli Mthembu, former city manager Sipho Nzuza, the deputy head of Durban Solid Waste (DSW) Robert Abbu, and the deputy head of supply chain management Sandile Ngcobo, all worked in concert as the main roleplayers in corruption and racketeering.

They were the main individuals who acted as primary persons in an enterprise that conspired to rig DSW contracts valued at over R320-million to favour their preferred contractors and sub-contractors, the State has said.