To prevent a sole executive from wielding excessive power, Nissan Motor Co. should abolish its chairman position and strengthen an independent monitoring governance system, a panel of experts commissioned by the carmaker said Wednesday.

Governance issues surfaced at the firm following the arrest of former Chairman Carlos Ghosn for alleged financial misconduct last November. Ghosn is alleged to have underreported billions of yen in income over the course of several years and shifted personal investment losses to the company.

The root cause of the alleged misconduct was the "concentration of all authority" in Ghosn, including areas like human resources and compensation, the panel's report said.