An individual shareholder of Toshiba Corp. has demanded that the company file a ¥1 billion damages suit against 28 current and former executives for ruining the firm's credibility by turning a blind eye to widespread mis-accounting.

If the Tokyo-based industrial conglomerate fails to do so within 60 days, the shareholder, who is in his 60s and from Nara Prefecture, threatens to take the case to the Tokyo District Court. He says he will do so in association with a lawyer from an Osaka-based legal team that works for shareholders' rights.

In his written request Tuesday, the man alleges that the executives, including former President Hisao Tanaka, knew of the improper accounting but failed to stop it or attempt to correct it. Tanaka resigned in July to take responsibility for the scandal.