AUSTIN, Texas

- A prosecutor who handled the case of a Texas man executed for the fire deaths of his three daughters has been formally accused of misconduct over allegations that he concealed evidence during the 1992 murder trial.

The State Bar of Texas has asked a Navarro County court to discipline John H. Jackson following questions raised by the New York-based Innocence Project and Cameron Todd Willingham's relatives, which investigates potential wrongful convictions. A spokeswoman for the bar said the punishments for Jackson could range from a reprimand to revoking his law license.

Jackson was the lead prosecutor against Willingham, whose case has become a flashpoint for death penalty opponents who contend that he was wrongly executed. Jackson, who has consistently denied any wrongdoing, declined to comment yesterday on the state bar's action. His attorney disputed the accusations.

Willingham maintained his innocence up until being executed in 2004.

"Before, during, and after the 1992 trial, [Jackson] knew of the existence of evidence that tended to negate the guilt of Willingham and failed to disclose that evidence to defense counsel," the bar's four-page complaint says.

The complaint was filed March 5 without any public announcement or fanfare. It was first reported by The Marshall Project, a nonprofit journalism group.

The case has been referred to a family court judge in Houston. Joseph E. Byrne, Jackson's attorney, said he has requested a jury trial.

"We're very confident that when a jury sees this evidence, they will find that John Jackson has not done anything wrong," Byrne said.

A key witness in the case against Willingham was inmate Johnny Webb, who testified that while in jail awaiting trial, Willingham confessed to Webb that he had killed the girls. Webb later recanted that testimony before Willingham was executed.