TOKYO—Nissan Motor Co.’s Carlos Ghosn was planning to replace the company’s chief executive before the plan was derailed by Mr. Ghosn’s arrest in Tokyo last month, according to people with knowledge of the matter.

Word of Mr. Ghosn’s plan adds a new twist to the drama inside Nissan. CEO Hiroto Saikawa has said the company was investigating possible misuse of corporate assets and other alleged wrongdoing by Mr. Ghosn for months this year and was supplying information to Tokyo prosecutors.

While...