A federal agent failed to tell the judge, who issued search warrants in the case, about the legitimate uses of steroids, according to a motion to suppress evidence against Dr. Phil Astin.

Arora did not elaborate on Benoit's condition, but said, "Had the magistrate judge known all these things, perhaps she wouldn't have issued the warrants, and there wouldn't have been a case here."

A spokesman for the U.S. attorney's office declined to comment.

Investigators have not given a motive for the killings, but the question of whether steroids played a role has lingered. The drug was found in Benoit's home, and tests showed Benoit had roughly 10 times the normal level of testosterone in his system when he died.

Authorities have said Astin prescribed a 10-month supply of anabolic steroids to Benoit every three to four weeks between May 2006 and May 2007.

Testosterone can be used as part of hormone replacement therapy. Some athletes also have been known to use steroids to enhance their performance.

The district attorney overseeing the death investigation has said Benoit strangled his wife with a cord, used a choke hold to strangle his 7-year-old son, then placed Bibles next to the bodies and hanged himself on a piece of exercise equipment in his Fayetteville home the weekend of June 22.

Astin has pleaded not guilty to federal charges of improperly prescribing painkillers and other drugs to two patients other than Benoit. Federal prosecutors plan a superseding indictment with new charges, but haven't said when they will act.

Last week, Arora asked a judge to throw out evidence seized from his client's west Georgia office on June 27. Monday's motion to suppress challenged the legality of raids on Astin's office on June 29 and his mother's home the same day.

Astin is free on bail, but must remain in his home except under limited circumstances. A pretrial conference is scheduled for Sept. 18.