They were acting on behalf of the Ekurhuleni metro municipality, which was defrauded of more than R21 million in a computer tender, said National Prosecuting Authority spokesman Mthunzi Mhaga.
"In the combined operation with the Hawks, the Special Investigating Unit (SIU), and the Anti-Corruption Task Team, we seized 12 residential homes, several trucks and 27 luxury cars and motorbikes," Mhaga said.
The vehicles included BMWs, Mercedes-Benzs and a Porsche.
The properties and vehicles were taken from seven people and three businesses. Mhaga said the buildings were in Irene, Edenvale, North Riding, Bedfordview and Benoni.
According to Mhaga, Valero David was the sole member of a company, Meropa Sechabeng Technology CC, which was awarded a computer tender by the municipality.
He was related, through marriage, to the executive director of the municipality's computer department, Nilesh Singh.
David failed to disclose this relationship when applying for the tender. Andrew Mphushomadi, a senior manager in the computer department, was also allegedly involved in awarding the tender and the ensuing fraud, Mhaga said.
Mphushomadi was a member of Nanga Transport CC.
"Shortly after the tender was awarded, Nanga took ownership of a number of Mercedes-Benz trucks valued at nearly R4 million," Mhaga said.
These vehicles were apparently paid for by Meropa.
Mhaga said after David was awarded the tender, he had used R8 million to buy luxury vehicles for the other accused and their families as a celebration.
David, Singh and Mphushomadi were arrested by the Hawks last year and appeared in the Pretoria Commercial Crime Court on fraud and corruption charges last July.
Their case is scheduled to continue on July 2 this year.