Pregnancy prevented Marion Jones competing at all in 2003

Francis was banned for life by Athletics Canada after his then protege Ben Johnson tested positive for steroids at the 1988 Olympics.

Jones and partner Tim Montgomery, the 100m record holder, were both coached by Francis at the start of 2003.

"The only regret is the way it was all handled," Jones said.

"I think that I learnt a lot from Charlie Francis."

Montgomery started working with Francis from November 2002, with Jones following suit in January 2003, before both ended the association in February 2003 following widespread criticism.

Last November both Jones and Montgomery were summoned before a grand jury investigating the drugs scandal that has enveloped the sport.

I know I am 100% clean Marion Jones

Jones gave evidence to the San Francisco grand jury investigating the Bay Area Laboratory Co-operative BALCO.

The laboratory and its founder Victor Conte had been linked by the United States Anti-Doping Agency to the development and distribution of the previously undetectable steroid tetrahydrogestrinone (THG).

Conte and three others have since been indicted.

Jones to take on Block

But Jones, who is in England to compete in the 60 metres at Birmingham's international indoor event, insisted she had done nothing wrong.

She said: "I know I am 100% clean."

Friday's competition will be the 28-year-old's second and final indoor competition of the year after she took 2003 off to have a baby.