Jamaica's Veronica Campbell reacts during the medal ceremony for the women's 200 metres at the Athens 2004 Olympic Games.

André Lowe, Staff Reporter

Jamaica's track and field is facing its darkest day since the 1999 Merlene Ottey doping scandal, after revelations that top Jamaican sprinter Veronica Campbell-Brown has tested positive for a banned substance at this year's Jamaica Invitational, staged on May 4 at the National Stadium.

Campbell-Brown, who was reportedly informed of the positive test on June 3, is Jamaica's most decorated female athlete, having won 16 medals for the country at the Olympic and World Championship levels alone.

However, the athlete's 'A' sample returned an adverse analytical finding after substances believed to be diuretics, which can act as a masking agent for performance enhancement drugs (PED) and are banned by the World Anti-Doping Agency was discovered after testing.

Diuretics are drugs that help the body to get rid of excess fluids, primarily through urination. They also decrease the ability to detect PEDs.

The athlete's B sample also reportedly returned a positive result yesterday and her sponsors have since been advised, while the IAAF are said to be preparing a statement in the coming days.

Campbell-Brown has also reportedly withdrawn from the Edmonton International Track Classic, which is set for June 29.

This latest doping setback is expected to have far-reaching impact on the reputation of Jamaica's track and field, particularly following recent cases against a number of the island's athletes, none, however, have been as high profile.

Eight Jamaicans have returned positive tests for banned substances over the past five years, casting a cloud of suspicion in some circles over the country's programme.

The nation faced similar anxiety in 1999 when Ottey; then the country's sprint darling, returned a positive test for the banned anabolic steroid nandrolone, at a meet in Lucerne, Switzerland.

Ottey, whose B sample also returned a positive test, was later cleared after the Court of Arbitration for Sport dismissed the case because the retesting was not completed in the allotted time.

Ottey has always maintained her innocence, stating at the time that she had not knowingly taken steroids. Numerous efforts to reach both the athlete and her agent Claude Bryan, since late Thursday, have proven to be unsuccessful.