Sprinter Florence Griffith Joyner, whose death at age 38 shocked the athletics world, suffered an epileptic seizure that caused her to suffocate, a coroner's report released yesterday said.

Griffith Joyner "died as a result of positional asphyxia, secondary to an epileptic seizure," said doctor Richard Sukumoto, a private physician who serves as chief forensic pathologist of the Orange County Sheriff-Coroner's Department.

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

She was lying face down on her bed at her home in suburban Mission Viejo at the time, and when the seizure caused her head to turn, her airway was blocked, Sukumoto said.

Toxicology tests showed she had taken Tylenol and Benadryl but "there was nothing unusual in terms of drugs" claimed an official. Other scientists said at the conference that her heart appeared normal.

Griffith Joyner set world records in 1988 at 100 and 200m that still stand. She won the Olympic title at both distances in 1988, and won 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.

But world record times that year, 10.49 sec in the 100m at the US Olympic trials and an astounding 21.34 in winning the 200m gold, sparked whispers that Griffith Joyner 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 lashed out at 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 September 21.

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.

"We now hope that this great Olympic champion, wife and mother can rest in peace, and that her millions of admirers around the world will celebrate her legacy to sport and children every day," said US Olympic Committee president Bill Hybl.

"It is time for the whispers and dark allegations to cease."