Canadian wrestler Chris Benoit had 10 times the normal amount of testosterone in his body when he hanged himself, officials said Tuesday.

"This level of testosterone indicates that he had been using testosterone some time prior to the day that he died," Dr. Kris Sperry, chief medical examiner for the Georgia Bureau of Investigation, said Tuesday.

It appeared to have been injected in Benoit's body shortly before he died, authorities said.

The testosterone, a synthetic version of the primary male sex hormone, is considered an anabolic steroid.

The elevated level "is an indicator that he had been injecting testosterone, but how much, how frequently, how often and for how long is something that cannot be answered through this," Sperry said.

Benoit's body also contained the anti-anxiety drug Xanax and the painkiller hydrocodone, authorities said.

However, there was no evidence to show that steroids played a role in the death of his wife and young son.

"An elevation of that ratio does not translate into something abnormal in a person's thought process or behaviour,'' Sperry said.

Benoit tested negative for alcohol, authorities said.

His wife Nancy's body also contained a "therapeutic" amount of sedatives in her body when she was killed, Sperry said at the news conference held in Decatur, Ga.

She tested positive for Xanax, hydrocodone and the painkiller hydromorphone.

Sperry noted that her body was decomposing and that would affect the ability to interpret results reliably.

Nancy also had a blood-alcohol level of .184. "All of this alcohol could be due to the decompositional process," Sperry said.

Sperry said their seven-year-old son Daniel also appeared to have been sedated when he was asphyxiated.

"It is our opinion that Daniel Benoit was sedated at the time that he was murdered," Sperry said.

The Xanax level in Daniel's body was "relatively elevated, and also, Xanax is not a drug that would normally be given to a child for routine purposes," Sperry said.

Authorities said tests for steroids or human growth hormones could not be performed on the boy because of a lack of urine.

Police say Benoit killed his wife and seven-year-old son in their home near Atlanta last month and then hanged himself on the cable of a weight machine.

Authorities found anabolic steroids inside the gated home, leading officials to wonder if the drugs played a role in the killings.

Some experts believe steroids can cause paranoia, depression and violent outbursts.

But Sperry warned that there was conflicting scientific information on whether steroids spark extreme anger, known as "roid rage."

"This a question that basically no one knows the answer to,'' Sperry said.

"There is conflicting scientific data as to whether or not testosterone creates mental disorders or leads to outbursts of rage,'' he said. "There's data that suggests it and other data that refute it.''

Physician arrested

Following the slayings, federal authorities arrested Benoit's personal physician, Dr. Phil Astin, with improperly prescribing painkillers and other drugs to patients other than Benoit. He has pleaded not guilty.

Investigators have raided Astin's office several times since the deaths, seizing prescription records and other medical documents.

Before he was charged, Astin told The Associated Press he prescribed testosterone for Benoit, a longtime friend, in the past.

Astin would not say what medications he prescribed when Benoit visited his office June 22, the day police believe Benoit killed his wife.

On Saturday, three weeks after Nancy and Daniel Benoit were murdered, friends and family paid their last respects at a private funeral service in Florida. Nancy Benoit's family lives in the state.

The Montreal-born Benoit was a World Wrestling Entertainment (WWE) superstar with a wholesome, family-man image.

Despite that appearance, however, his wife filed for divorce in 2003, alleging "cruel treatment.''

She later dropped the complaint, as well as a request for a restraining order in which she alleged Benoit threatened her and smashed furniture.

Nancy was a wrestling stage manager who married Benoit, described as "The Canadian Crippler" in the ring, in 2000.

Benoit's father has said private services for him were to be held in Canada. It's not known whether those services have taken place.

WWE owner Vince McMahon, who did not show up to the funeral of Nancy Daniel, has urged the public not to assume steroids were behind the double murder-suicide.

A WWE statement said Benoit passed a random drug test in April.

With files from The Associated Press