American long jumper Jarrion Lawson has been provisionally suspended by the Athletics Integrity Unit (AIU) after failing a drugs test.
The 24-year-old World Championship silver medallist tested positive for epitrenbolone - a metabolite of banned steroid trenbolone.
Lawson has been served with a notice of allegation and will not be able to compete prior to a full disciplinary hearing.
He won his world silver medal in London last year, finishing only four centimetres behind South Africa's Luvo Manyonga with a jump of 8.48 metres.
The American finished fourth at the Rio 2016 Olympic Games in Brazil and was a bronze medallist at the World Junior Championships in Barcelona in 2012.
Also a sprinter, Lawson achieved a memorable treble at the 2016 National Collegiate Athletic Association Outdoor Championships by winning the 100m, 200m and long jump.
The feat had only been achieved previously by the legendary Jesse Owens.
Lawson is facing a four-year ban with trenbolone usually used to build muscle mass.
It was one of three drugs used in the infamous "Duchess cocktail" - said to be given to Russian athletes as part of their manipulation of the doping scheme at their home Sochi 2014 Winter Olympics.
The AIU have not yet confirmed the date and place of Lawson's failure.