In the wake of the scandalous $1.7 billion collapse of Diagnostic Ventures Inc., investors have won the right to pursue class action fraud claims against the firm’s auditors at Deloitte & Touche, but lost their bid to bring class claims against lawyers from Clifford Chance.

The 3rd U.S. Circuit Court of Appeals has ruled that the auditors were properly sued under a fraud-on-the-market theory for allegedly issuing “clean” audit reports that hid DVI’s improper accounting practices.