SYDNEY: Six Australian swimmers risk losing their Olympic medals after Brenton Rickard, who was part of the men’s 4×100 metre medley team that won bronze at the 2012 London Games, tested positive for a banned substance, the Age reported on Friday. A re-analysis of the sample Rickard gave eight years ago revealed what his lawyers said was an “exceedingly small concentration” of Furosemide, a banned masking agent, the report in the Melbourne newspaper said. The Australian Olympic Committee said they were unable to comment as there was a process in place. Australia have not lost an Olympic medal because of any drug case. The Age also published an email from the now-retired swimmer to his former team mates sharing what the 37-year-old called his “worst nightmare”. In the mail, Rickard said he took over-the-counter medications in the week prior to the test in 2012, which might have contained the diuretic. Rickard said he would be fighting any move to disqualify results of the medley relay team at the London Games in a Court of Arbitration for Sport (CAS) hearing beginning on Monday. Rickard swam alongside Hayden Stoeckel, Matt Targett and Tommaso D’Orsogna as Australia set the fourth fastest heat time in the Olympic relay. Christian Sprenger replaced Rickard and James Magnussen substituted D’Orsogna in the final where Australia finished behind United States of American and Japan.