Proxy adviser Glass Lewis & Co. blasted Toshiba Corp.'s board for poor governance amid repeated scandals and recommended investors vote against all directors at the company's shareholders meeting this month.

In a 25-page report, the U.S. firm details years of accounting troubles at the Japanese icon, clashes with accountants over financial statements, weak internal controls and management missteps that have put investors at risk of seeing their shares delisted from the Tokyo Stock Exchange.

Toshiba said in 2015 that it had overstated profits for seven years and paid a record fine, only to reveal this year that it would have to take a write-down in its nuclear business of more than $6 billion.