Be My Royal, winner of the one the biggest races of the National Hunt season to date, faces disqualification in connection with a rash of positive drug tests for traces of morphine in British and Irish races due to contaminated feed.The situation has brought a call for thresholds for morphine and other substances that may occur through environmental contamination.Successful in the £105,000 Hennessy Cognac Gold Cup Chase at Newbury in late November, the Irish-trained horse, from the barn of Willie Mullins, is one of 28 runners to date in Britain to return a morphine positive to tests carried out by the Horseracing Forensic Laboratory at Fordham near Newmarket. These results, which include 13 winners, are being double-checked by overseas laboratories in the normal way, and the results of the "B" sample tests are likely to start arriving shortly. The Jockey Club is expecting the British positives to rise above 28.The situation in Ireland is that nine horses (eight of them winners) have tested positive for morphine, and the B samples have been confirmed in eight cases.Irish feed company Red Mills has identified and isolated the source of the traces of morphine, which its said were too low to affect the performance of the horses involved. Red Mills reports the morphine was naturally occurring in one of the feed inputs, and more sophisticated testing of that input, which it has not specified though some speculate on poppies in a batch of barley, is now taking place and its racehorse feeds are safe to use.All the contaminated batch has been recalled, and over the Christmas break, Red Mills wrote to all its customers.European racing authorities currently have a blanket ban on morphine with no threshold level because the drug is a potent pain killer that could improve a horse's performance. Apparently, the British tests have revealed wide variations in the levels -- albeit at fairly low concentrations -- of morphine, which is derived from certain species of poppy.Red Mills, which faces costly compensation claims from owners, breeders, trainers, and jockeys, argues that the level of testing at racing laboratories is so sophisticated that feed companies are being asked to screen ingredients to the same level and only usually find out about problems after they have occurred. The company has called for threshold levels to be introduced, and the European-wide scientific liaison group which discusses such matters is in fact looking into thresholds for banned substances which have no impact on performance.