The 17-year-old is the current world under-20 champion in the 100 and 200 metres, with a personal best of 10.94sec in the 100m.

She recorded that time at the Jamaican Championships in June, booking her place at the IAAF World Championships but also reportedly tested positive for the banned substance. 

Williams's representative Emir Crowne has claimed that the substance was contained in an over-the-counter cold-and-flu medication that was given to her by a close relative, but was not listed as an active ingredient, as reported by Jamaican newspaper The Gleaner.

It is also reported that Williams had declared the medication on her doping control form while being tested by Jamaica Anti-Doping Commission officials. 

She was made aware of the result on July 25.

Williams had been due to compete at the Pan American Games in Lima last month but travelled to the Peruvian city without competing.

"Our primary position will be that Ms Williams bears no fault in the circumstances and there should be no sanctions levied against her," Crowne said. 

"That will be our primary position. 

"It will be an uphill battle, but this is one of the truly genuine times when there was nothing more that the athlete could do in the circumstances."

It is hoped that a hearing for Williams will be expedited, with the Jamaican team for the World Championships set to be named on Friday (September 6). 

Williams is coached by Ato Boldon of Trinidad and Tobago, the men's 100m Olympic silver medallist at Sydney 2000. 

In 2001, Boldon tested positive for the stimulant ephedrine but was only given a warning, as the substance can be found in many over the counter remedies.

The news regarding Williams is the latest doping scandal to rock athletics, with America's Christian Coleman, the fastest man in the world for the past three years, allegedly missing three drugs tests over a 12-month period. 

He is due to face a hearing on Wednesday (September 4).