ATLANTA (AP) — The State Bar of Georgia has asked for an investigation into Republican House Speaker David Ralston.

A petition filed Thursday in state Supreme Court accuses Ralston of questionable practices in a 2008 case involving Paul Chernak of Cumming, who was seriously injured in a crash.

The State Bar of Georgia is asking the high court to appoint a special master to investigate.

The petition accuses Ralston of allowing the man's case to languish for years while he served in the Georgia Legislature and failing to inform Chernak of its status.

The petition also accused Ralston of advancing Chernak $22,000 to pay personal expenses. The petition said Ralston tapped his attorney trust account to pay the man with his own money and money that belonged to other clients.

The petition said Chernak eventually sought out a new lawyer to represent him in the case.

The petition accused Ralston of violating several areas of the Georgia Rules of Professional Conduct including diligence, communication, and expediting litigation. Penalties linked to offenses Ralston is accused of range from public reprimand to disbarment.

Ralston's spokesman Marshall Guest said the House Speaker vigorously defends his professional reputation and will fully cooperate with the investigation.

"For more than 34 years as a practicing attorney, he has shown that he cares very deeply about his clients' legal rights," Guest wrote in an emailed statement.

He added that Ralston will "continue to respect the attorney-client privilege with regard to the specifics," despite the deterioration of his relationship with the client.

Ralston, of Blue Ridge, has served in the legislature since 2003 and was elected House Speaker in 2010.