The world record-holder was banned by the International Amateur Athletics Federation following a positive test for cocaine during the Pan-American Games at the end of July.

But the CAF announced that following a investigation, the charges had been dropped.

The incident echoes the cases of British sprinters Linford Christie and Dougie Walker, who both failed dope tests only to have the allegations withdrawn by their own governing body, UK Athletics.

CAF president Alberto Juantorena said: "We have undertaken a very precise study of the affair.

"The experts have confirmed that a man with the quantity of cocaine found in the urine of Sotomayor would not have been able to stand upright. He would therefore have jumped even less high.

"We will not be putting any sanctions on Sotomayor. We will explore absolutely every channel within our power in order for his honour to be cleansed," he told L'Equipe newspaper.

Rash of scandals

The Sotomayor doping row is just the latest scandal to hit the athletics world.

Linford Christie: Waiting for IAAF decsion

News of failed drugs test had shocked Primo Nebiolo, President of the International Amateur Athletics Federation.

"I am shocked and cannot believe it," he said at the time. "I am very surprised and upset, because I have great esteem for Sotomayor.

UK Athletics is set for a battle with the IAAF, after it's decision to clear former Olympic 100m champion Christie of using the drug nandrolone.

The Briton was cleared by a three-man disciplinary committee of the British governing body.

Conflict over nandrolone

The IAAF has already described UK Athletics' decision over Walker as erroneous and has referred it to its arbitration panel, which will also be the likely reaction from the Christie findings.

UK Athletics spokeswoman Jayne Pearce said it could not be proved that the substance found in Christie's urine was the banned drug nandrolone.

She said two other substances, which were not on the International Olympic Committee (IOC) or IAAF banned lists at the time of the test, could have caused the positive result.

"The substance found in the urine sample could not be clearly related to a banned substance," Pearce said.

"We agree with strict liability as well, if there's a banned substance.

"But there were two other substances as well as nandrolone which could have caused the finding."

The IAAF Doping Commission will now study the document relating to the Christie decision and make a recommendation to the IAAF Council.

Other sports stars that have been found guilty of the use of nandrolone include Jamaican women's 100m and 200m sprinter Merlene Ottey, Czech tennis player Petr Korda and France's Olympic judo champion Djamel Bouras.