Yakup Öner, an engineer who used to work at Istanbul Metropolitan Municipality (IBB), exposed, as part of the widespread corruption case, how the municipal officials rigged tenders involving Istanbul’s former mayor, Ekrem Imamoğlu, an opposition favorite.

Öner, who was released earlier after he agreed to collaborate with authorities, testified on Wednesday at the hearing on what prosecutors call the "Imamoğlu criminal organization” at a courthouse in Istanbul.

He told the court that during his tenure at the municipality, he found out that municipal officials were in talks with certain companies before tender processes and sought payment of "7% to 10% of the tender price” to award tenders.

"I found out that cash or similar payments had been requested from some companies doing business with the municipality during the election period,” he said. Some witnesses and defendants in the case have claimed that Imamoğlu and his associates collected cash through bribes to fund Imamoğlu’s Republican People’s Party (CHP) and his future campaign in presidential elections.

At the hearing, defendant Öner also described an annual salary of $100,000 (TL 4.9 million) that Ekrem Imamoğlu allegedly gave him unofficially in a bag, apparently as hush money.

The indictment stated that Öner had been part of the criminal organization led by Imamoğlu from its establishment. It alleged that Öner conveyed to Imamoğlu the details of his meetings with prominent businesspeople concerning structures located within the Bosporus scenic zone where new construction is either strictly regulated or prohibited based on zoning plans. The indictment also stated that, in line with Imamoğlu’s instructions, municipal officials requested "charitable donations, construction of nurseries, schools and libraries” as bribes in exchange for issuing otherwise unattainable permits.

Öner said Imamoğlu had requested the construction of a nursery worth $700,000 in exchange for a strengthening permit for a villa and had also asked a company to waive a TL 10 million receivable from the municipality in exchange for a strengthening permit.

Regarding the allegation that a $10 million bribe was demanded to refrain from taking action over zoning violations involving a building owned by a prominent company, Öner said, "The structure related to (the nightclub) Reina dates back to before 1950 and is therefore legally considered to have an occupancy permit. Accordingly, under the regulations, it is possible to issue a strengthening permit for structures with occupancy permits. The relevant company’s request was for this purpose. Ekrem Imamoğlu conveyed this matter to me. He told me about the company’s requests and said, ‘Let’s ask them to waive $10 million of the total amount they are owed by the rail systems,” he said,” referring to the municipality’s debt to the said company, which also undertook a rail project for the municipality.

In another instance, Öner said Imamoğlu told him to ask a construction company to build a dormitory and hand it to the municipality in exchange for a building permit.

Asked about the annual $100,000 salary that Imamoğlu allegedly gave him unofficially, Öner said: "I was an employee working outside the institution when I had my own company. Naturally, you establish a certain standard of living for yourself. When you are told to maintain that standard while working at the institution, you cannot change it. Therefore, I made such a request. He was kind enough not to turn me down, but this was an annual $100,000 regardless of the nature or quality of the work I was doing.”

When the prosecutor asked whether the money came from municipal funds or was paid by Imamoğlu himself, the defendant replied, "I received it from him.”

When asked whether the money was handed over in cash, the defendant said, "Yes, I received it in cash. I would receive it from him in the environment where he was.”

The prosecutor then asked, "Did Mr. Ekrem carry the money around by taking it out of his pocket?”

The defendant replied, "No, not in his pocket. I received it in a bag.”

"None of the businesspeople willingly or gladly accepted the high amounts of payments during any of the meetings. They somehow made it clear that they were not making the payments willingly. They felt that their future relationships and business dealings depended on these payments. Therefore, they felt they had to make them,” he said.