Anabolic steroids were found in Benoit's suburban Georgia home raising questions whether the steroids which some experts say cause paranoia, depression and violent outbursts known as "roid rage" played a role in the slayings.
McMahon said toxicology results were needed to answer questions surrounding the death of Benoit, who hanged himself on the cable of a weight-machine in his home this week. Authorities said he strangled his wife and smothered his son over the weekend and placed Bibles next to their bodies.
"There's no way, quite frankly, that we, or the media _ it's all speculation until the toxicology reports come back," McMahon said, speaking on NBC's "Today" talk show. "It's all speculation."
The WWE, based in Stamford, Connecticut, was quick to dismiss the idea that steroids played a role, issuing a news release Tuesday saying they "were not and could not be related to the cause of death" and that the findings indicate "deliberation, not rage." Benoit tested negative April 10, the last time he was tested for drugs, the WWE said.
Toxicology test results may not be available for weeks or even months, District Attorney Scott Ballard has said.
No motive has been offered for the killings.
The couple argued in the days before the slayings over whether he should stay home more to take care of their mentally retarded son, said Jerry McDevitt, an attorney for the league.
McDevitt said the wrestling organization learned from the couple's friends and relatives that the Benoits were struggling with where to send the boy to school since he had recently finished kindergarten.
He also said Benoit's wife did not want him to quit wrestling, but she "wanted him to be at home more to care for the kid. She'd say she can't take care of him by herself when he was on the road."
The child suffered from a rare medical condition called Fragile X Syndrome, an inherited form of mental retardation often accompanied by autism, McDevitt said.
Meanwhile, authorities in Georgia were investigating a link between Benoit and a Florida business that may have supplied him with steroids.
Prosecutors in upstate New York who have been investigating the company's drug sales said Benoit received deliveries from Signature Pharmacy and MedXLife.com, which sold steroids, human growth hormone and testosterone on the Internet.
Six people, including two of the pharmacy's owners, have pleaded guilty in the investigation, and 20 more have been arrested, including doctors and pharmacists.
Terence Kindlon, lawyer for MedXLife co-owner Dr. Gary Brandwein, denied the allegations that his client's company sold steroids to Benoit. Brandwein has pleaded not guilty to six counts in New York state court related to the criminal sale of a controlled substance. He was accused of signing and sending prescriptions without ever seeing patients.
McDevitt said the drugs found in Benoit's house were legitimately prescribed. "There's no question, none of these drugs are out there, none of these drugs came from Internet pharmacies," he said.
In addition to causing paranoia and explosive outbursts, steroids can also contribute to deep depression, according to experts.