Mohamed Iqbal Khan stepped down as an independent director of the Cricket South Africa (CSA) board on Wednesday.
Earlier on Tuesday, Professor Shirley Zinn had resigned as an independent director citing a problem with CSA's "principles of corporate governance".
"I cannot believe you are not aware of the many issues that have caused this malaise and to that extent, you are also complicit, and perhaps even the entire board," ESPNcricinfo quoted Khan as saying in his resignation letter.
"However, I can no longer be part of an organisation that is fast ruining the game," he added.
Khan's letter also revealed that CSA had scheduled a board meeting on Tuesday, which was later postponed to Saturday. More resignations are expected before then.