Two investors have filed a class action suit against Philadelphia-based Astor Weiss Kaplan & Mandel, alleging that the firm should have known its client, Mantria Corp., for whom it served as securities counsel, was engaged in a $54 million Ponzi scheme.

The suit had originally been filed last year in the U.S. District Court for the District of Colorado, but in December, then-Chief Judge Wiley Y. Daniel granted Astor Weiss’ motion to dismiss for lack of personal jurisdiction.