Jamaican track star Veronica Campbell-Brown has been tested positive for a banned substance.Campbell-Brown was tested positive at the Jamaica Invitational Meet on May 4.Campbell-Brown's A sample revealed the presence of a diuretic, which acts as a masking agent and is banned by the World Anti-Doping Agency.Diuretics are used to cause the excess release fluids from the body primarily through urination, as a result, decreasing the ability to detect performance enhancement drugs.She travelled to Montreal, Canada with her management team on Thursday ahead of the B sample results, which on Friday confirmed the positive finding.Campbell-Brown was informed of the finding on June 3 and her sponsors have reportedly since been updated.The International Association of Athletics Federations is expected to make an announcement this week.