Duncan Kennedy: "She remained an inspiration to women athletes"

Three-time world hurdles champion Greg Foster, a friend of the family, said: "We have lost one of the great track and field athletes in history. She's going to be missed. It's definitely a shock, a great loss."

Griffith Joyner, known by her fans as Flo-Jo, captivated the world with her phenomenal speed and flamboyant style but her rapid improvement and her tremendous physique fuelled rumours about performance-enhancing drugs.

Jamaican athlete Juliette Cuthbert: "I'm just blown away by the news"

She was the wife of 1984 Olympic triple-jump gold medalist Al Joyner and the sister-in-law of Jackie Joyner-Kersee, the six-time Olympic medalist and world heptathlon record-holder.

Griffith Joyner set women's 100 and 200-metre world records in 1988.

Famous fingernails

Known for her self-designed running uniforms and six-inch painted fingernails, she also won a 1984 Olympic silver medal in the heptathlon and 1992 bronze medal in the long jump.

Florence Griffith Joyner in action

Griffith Joyner first captured the headlines with an amazing series of runs in the US Olympic trials in 1988 and became the first woman to run the 100m in 10.49 seconds.

At Seoul she won the 100m in a wind-assisted 10.54, then set two world records at the 200m, running the semi-final in 21.56 and the final in 21.34.

Denied taking drugs

She retired immediately after the 1988 Games, amid a swirl of rumours about her taking performance-enhancing substances. She always denied the accusations and never failed a drugs test.

She married Al Joyner in October 1987 and had a daughter Mary, who was nicknamed Mo Jo by the US press.

Jamaican athlete Juliette Cuthbert, who ran against Flo-Jo in 1988, said Griffith Joyner had another seizure on board an aeroplane in 1996.

Death of a role model

Her premature death is bound to raise questions about her lifestyle and resurrect allegations of drug-taking.

But US Olympic committee president Bill Hybl said: "She was a role model for girls and young women in sports and her legacy will be one that included kindness and an interest in children."

Primo Nebiolo, president of the International Amateur Athletics Federation, said: "It's a great shock and makes me extremely sad.

"I knew that Florence Griffith Joyner had had some heart problems in recent months but I didn't think it was anything really serious."

Mr Nebiolo said: "Sadly her life has passed as rapidly as her races."