updated 2:58 p.m. ET July 4, 2007

ATLANTA - The pro wrestler who strangled his wife and son and committed suicide last month bought injectable steroids excessively, according to court papers released Monday. His doctor was charged with improperly prescribing drugs to other patients.

Dr. Phil Astin prescribed a 10-month supply of anabolic steroids to Chris Benoit every three to four weeks between May 2006 and May 2007, a Drug Enforcement Administration agent said in an affidavit filed Friday and made public Monday.

During a probe of “RX Weight Loss,” Benoit was identified as an excessive buyer of injectable steroids, the document states. Prosecutors would not say what “RX Weight Loss” is.

The affidavit also said Astin supplied various controlled substances, including injectable anabolic steroids, that were found in Benoit’s home.

Astin has not been charged with supplying steroids to Benoit, though U.S. Attorney David E. Nahmias said more charges are possible.

The anabolic steroids found in Benoit’s home led officials to wonder whether the drugs played a role in the killings that started the weekend of June 22. Some experts believe steroids can cause paranoia, depression and violent outbursts known as “roid rage.” Toxicology tests on Benoit’s body have not been completed.

A federal indictment issued Monday charges Astin with improperly dispensing painkillers and other drugs to two different patients.

Prosecutors allege in the seven-count indictment that Astin dispensed drugs including Percocet, Xanax, Lorcet and Vicoprofen between April 2004 and September 2005. The recipients were identified in the indictment by the initials O.G. and M.J.; Benoit’s initials were not listed.

Astin pleaded not guilty and was being held in lieu of $125,000 bond. He will be under house arrest once he posts bond and must surrender his medical license, U.S. Magistrate Judge Linda Walker ordered.

Astin had written prescriptions for about 1 million doses of controlled substances over the past two years, including “significant quantities” of injectable testosterone cypionate, an anabolic steroid, according to the criminal complaint.

The complaint by Drug Enforcement Administration agent Anissa Jones said the amount of prescriptions was “excessive” for a medical office with a sole practitioner in a rural area like Carrollton, about 40 miles west of Atlanta.

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Assistant U.S. Attorney John Horn said that when agents raided the doctor’s office Wednesday, Astin was carrying Benoit’s medical file.

Astin’s attorney, Manny Arora, said the doctor had brought the file because he thought the authorities would want it.

Federal drug agents have taken over the probe into whether Astin improperly prescribed testosterone and other drugs to Benoit before the killings and suicide in the wrestler’s suburban Atlanta home last month. State prosecutors and sheriff’s officials are overseeing the death investigation.

Investigators have conducted two raids at Astin’s west Georgia office since last week.

Astin prescribed testosterone for Benoit, a longtime friend, in the past but has not said what, if any, medications he prescribed when Benoit visited his office June 22, the day authorities believe Benoit killed his wife.

“We’re still asking questions and searching for answers with regard to the death so we can tie up loose ends,” said Scott Ballard, Fayette County district attorney.

Authorities have said Benoit strangled his wife and son, placing Bibles next to their bodies, before hanging himself with the cable of a weight machine in his home.

The boy had old needle marks in his arms, Ballard has said. He said he had been told the parents considered him undersized and had given him growth hormones.

Benoit’s father, Michael, said Monday that “it’s impossible to come up with a rational explanation for a very irrational act.”

“Let the cards fall where they fall, we have no control over it at this point,” he said.