Japan's trade ministry effectively colluded with Toshiba's management.
That's according to an independent probe.
It found that the ministry sought to influence shareholder votes on director nominees at last year's annual general meeting.
Now the findings could discredit government efforts to improve corporate governance in Japan.
The investigators' report lays out how the Ministry of Economy, Trade and Industry leaned on Harvard University's endowment fund and other foreign investors in Toshiba.
It says the firm actively sought official help in countering activist investors, and investigators say there is suspicion that laws were violated in many places.
Takao Nakamura is an investigator:
"Toshiba was found to have devised a plan to effectively prevent shareholders from exercising their shareholder proposal right and voting rights at the annual general meeting by putting undue influence on Effissimo, the Harvard fund and another fund, 3D Investment Partners."
Thursday's (June 10) revelations come after top shareholder Singapore-based Effissimo Capital Management and other activists in March successfully pushed for an investigation.
That was widely considered a landmark win for shareholder activism in Japan.
Since then, the scandal-hit Toshiba has seen its former chief executive resign with the ensuing turmoil leading to a $20 billion bid for the conglomerate from CVC Capital.
While Toshiba has dismissed that bid, it has announced it will conduct a strategic review.
The probe also found that Toshiba, with the ministry, tried to force Effissimo to withdraw shareholder proposals for board nominees aimed at improving governance.
Toshiba and the ministry both said they were reviewing the contents of the report.