At the 1997 World Championships in Athens, Richardson ran the anchor leg for Great Britain in the 4 × 400 m relay, winning the silver medal. His unofficial split time was 43.5. On 7 January 2010 it was announced that Great Britain's 1997 World Championship 4 × 400 m relay team are to be awarded the gold medal; they were beaten by a U.S. team that included Antonio Pettigrew, who admitted in 2008 to using performance-enhancing drugs.[3]
Richardson received a two-year ban from the IAAF after he failed a drugs test which was taken on 25 October 1999. He was suspended in March 2000 and subsequently missed the 2000 Olympics in Sydney.[7] He tested positive for banned substance nandrolone, but claimed that he was unaware of taking the substance.[8] Unlike fellow competitors Linford Christie, Gary Cadogan and Doug Walker, Richardson accepted the ban and chose not to pursue his case to arbitration.[8] The IAAF did re-instate Richardson in June 2001, under their "exceptional circumstances" rule.[9]UK Athletics also cleared Richardson (as they did with Christie, Cadogan and Walker) as they believed there was enough reasonable doubt over the intention to take a banned substance.[8] The IAAF overrule such decisions because they hold athletes completely responsible for drug samples under a "strict liability rule".[8]
Later career and retirement
Although he was re-instated to competition in 2001, Richardson was never able to deliver on the potential that he showed prior to his ban when he became one of the few athletes ever to beat Michael Johnson over 400m in 1998.[10] He never managed to win a solo gold medal at a major championship and retired from the sport after failing to recover from an Achilles tendon injury towards the end of 2003.[11]