US Olympic 1500m contender Houlihan banned for four years despite burrito excuse

• 28-year-old says positive test was due to contaminated burrito
• Athlete was expected to be medal contender at Tokyo Olympics

The US 1500m and 5,000m record holder Shelby Houlihan has been banned for four years for doping after her claim that she ate a contaminated pork burrito 10 hours before a positive test for nandrolone was rejected.

In a statement Houlihan, who ran an area record 3min 54.99sec over 1500m to finish fourth at the 2019 world championships and was considered a leading Olympic medal contender for this year's Tokyo Games, claimed that she had never even heard of nandrolone" when she was first told of the news by the Athletics Integrity Unit (AIU) in January.