A class action lawsuit filed against Morgan Stanley in Broward Circuit Court in Florida alleges the financial behemoth allowed an investment adviser to trade stocks she was statutorily barred from trading.

The lawsuit, filed late Tuesday, claims that although the Securities and Exchange Commission barred West Palm Beach financial adviser Shelley Cohen from trading over-the-counter securities in the 1980s, Morgan Stanley’s predecessor Dean Witter incorrectly told her in 1995 that the ban had been lifted.