Karen Mullally on the coroner's conclusions and the drug allegations

According to the report, the seizure was brought on by a congenital defect in Griffith Joyner's brain called a cavernous angioma.

At the time of her death a month ago, it was reported she had died of a heart seizure - which some former athletes saw as evidence that she had suffered physical damage from steroid abuse.

Reporter Steve Futterman: "All the report talks about is her condition at time of death"

Doctor Richard Fukumoto, who serves as chief forensic pathologist of the Orange County Sheriff-Coroner's Department, found:"Florence Griffith Joyner died as a result of positional asphyxia, secondary to an epileptic seizure."

Doctor Barbara Zaias, a neuropathologist, said: "It is an abnormality that is congenital, meaning it is formed early on at the time the brain is developing in early gestation,"

She said there was no way to anticipate when the condition would cause symptoms such as a seizure or even a headache.

Fit while sleeping

None of the doctors or officials participating in the news conference to announce the autopsy results would discuss Griffith Joyner's previous medical history.

Her family have rejected rumours about her death

Dr Fukumoto said Griffith Joyner was apparently sleeping face down when the seizure occurred.

"During the epileptic form seizure, there was a tendency to turn the head towards one side.

"And during that process, there was a partial obstruction of the airway, resulting in a relative lack of oxygenation in the lungs.

"In addition, in this case, she was lying in a prone position - so the bedding and the pillow also contributed to it," he said.

Small amounts of non-prescription drugs were also found in Griffith Joyner's body. They included the pain reliever acetaminophen, known by the brand names Tylenol and Paracetamol among others.

She had also taken an antihistamine, said Director of Forensic Science for the coroner, Frank Fitzpatrick, but it would not have made her so groggy that it contributed to her death.

Griffith Joyner set world records in 1988 at 100 and 200 metres that still stand.

In 1988, she won the Olympic title at both distances and took a third gold medal that year in a relay.

She also stamped her image on the Games with her provocative one-legged racing outfits, dazzling fingernails and streaming hair.

Relatives condemn rumours

But world record times that year, 10.49sec in the 100m at the US Olympic trials and an astounding 21.34 in winning the 200m gold, sparked whispers that she had used performance enhancing drugs.

Griffith Joyner never tested positive for any banned drugs and she vehemently denied using them.

Since her death, her family and friends have condemned those who raked over the rumours.

Her defenders include her husband Al Joyner, the 1984 Olympic triple jump champion, who discovered his wife's body in bed on the morning of 21 September.

Among her most vocal supporters was his sister Jackie Joyner-Kersee, the heptathlon world record holder, and Joyner-Kersee's husband and coach Bob Kersee, who also coached Griffith Joyner.