Four Toshiba Corp. directors called on Friday for a shake-up of its management and board, in a sign of revolt after an investigation found the conglomerate colluded with the Japanese government to "beat up" foreign shareholders.

The very public pushback by the independent directors, all non-Japanese, is the latest twist in a scandal that shows how the old guard of Japan Inc., while still powerful, can no longer exert full control over shareholders.

It comes a day after an explosive, shareholder-commissioned investigation revealed — in startling detail rare for such probes in corporate Japan — how management reached out to the powerful Ministry of Economy, Trade and Industry (METI) to strong-arm activist investors.