Wrestler Chris Benoit, shown in 2004, was found dead at his Atlanta-area home along with his wife and son on June 25. ((Darryl Dyck/Canadian Press))

Testosterone was the only steroid found in toxicology tests on Canadian pro wrestler Chris Benoit, who police believe killed his wife and son before taking his own lifeat their Georgia home.

Investigatorshad wondered whethersteroid abuse,believed to cause depression andangryoutbursts known as "roid rage,"played a role in the double murder-suicide.

Benoit is believed to have killed his 43-year-old wife Nancy and their seven-year-old son, Daniel,before hanging himself in the weight room of their gated home just outside Atlanta. Their bodieswere found on June 25, but police suspect they may have been killed days earlier.

Kris Sperry, Georgia chief medical examiner, announcedthe toxicology resultson Tuesday afternoon but said the tests did not shed any light on whetherdrug usage played a role in the deaths.

The level of testosterone found in the wrestler's urine sample was 207 micrograms per litre, Sperry said.

"We were able to ascertain that this level of testosterone indicates that he had been using testosterone at least within some reasonably short period of time before he died," said Sperry. "There were no other steroid or artificial steroid-like drugs found in his urine."

Other drugs found in Benoit's body — the anti-anxiety drug Xanax and the painkiller hydrocodone — were at levels normal for therapeutic use, said Sperry.

Son sedated at time of death

Xanax was also found in the boy's body at 110 micrograms per litre, a "relatively elevated" level, said Sperry. The drug is not commonly prescribed to children.

"Based on this finding and the autopsy findings, it is our opinion that Daniel Benoit was sedated by Xanax at the time that he was murdered," said Sperry.

Three different drugs— Xanax, hydrocodone andthe painkillerhydromorphone— were found in Nancy's body, though Sperry said all were at levels indicating therapeutic use.

Nancy's blood-alcohol level was raised, but that may be a result of the decomposition process, said Sperry.

"Before she died[the level] may have been higher, they may have been lower. We just don't know and will never," said Sperry.

Two weeks ago, the wrestler's doctor was charged with improperly dispensing testosterone and other drugs in connection with the Benoit case.

The Montreal-born Benoit competed with World Wrestling Entertainment (WWE), beginninghis wrestling career in 1985 after training with Stu Hart and his family in Calgary.