Two members of imprisoned financier Bernard Madoff’s inner circle were arrested on charges of helping to conceal the largest financial fraud in history, U.S. prosecutors said on Thursday.

The indictments of former employees Jo Ann Crupi, 49, and Annette Bongiorno, 62, brings to eight the number of people criminally charged since the December 2008 revelation of Madoff’s multibillion-dollar, decades-long fraud.

Bongiorno worked at the Madoff firm for 40 years and Crupi was employed there for 25 years.