Bank of America fired at least two employees in its hedge-fund-focused prime brokerage unit as it expands an investigation into potential sexual misconduct in the business, people familiar with the matter told The Wall Street Journal.

The bank fired two employees after determining they interfered with the probe of alleged inappropriate behavior by Omeed Malik, until recently one of the top executives in the unit, the people familiar with the matter said. The fired employees had earlier been placed on leave, the people said.