Hugo Simon, Austria's most successful showjumper, could be stripped of his European championship silver medal after allegations that his horse, ET, was injected with an as yet unknown substance between the two rounds of yesterday's individual final in Mannheim.

Hans Wallmeier, a steward working under the International Equestrian Federation (FEI) medication control programme, saw two of Simon's employees in ET's stable and observed Simon's Dutch stable jockey, Pascal Uyttendaal, holding a syringe near the horse's neck. Wallmeier asked the two employees to leave the stable and, during a search, found the syringe in the straw.

Wallmeier confiscated the syringe, which was found to contain fresh blood, and reported the incident to Dr Peter Cronau, head of the veterinary committee at the championships. The judges agreed to let Simon jump in the second round, subject to his horse being kept under strict observation, and a clear round clinched the individual silver for the Austrian behind German favourite Ludger Beerbaum.

Immediately after the closing ceremony, when the medals were presented by German chancellor Helmut Kohl, Dr Cronau gave a statement on the incident to the appeals committee. Uyttendaal was interrogated and denied having injected the horse or having hidden the syringe. Simon's groom denied having seen anything.

A blood sample was taken from ET and both the sample and the syringe found in the stable have now been sent to Newmarket for testing. The results from ET's blood tests are expected to be known within the next two weeks.

The allegations were a controversial finish to an otherwise superb championships, but Trevor Coyle's brilliant rally with the stallion Cruising came too late to allow him any greater improvement than seventh in the final rankings.