Two of Connecticut’s most successful trial lawyers, Michael Koskoff and Kathleen Nastri, have been charged with new ethical misconduct allegations arising from a dispute over $4.6 million in legal fees from a medical-malpractice case.

The charges were filed by Chief Disciplinary Counsel Karyl Carrasquilla 13 days after a Statewide Grievance Committee panel rejected a plea agreement between Carrasquilla and Nastri. Nastri was willing to accept a reprimand for failing to retain clients’ financial records. However, after the three-member panel turned down the settlement, Carrasquilla added significant new allegations against Nastri and Koskoff, questioning the propriety of a retainer fee agreement in a case that resulted in a $25 million settlement.