The Kenyan placed fifth in the 10,000m final at the Paris Olympics and is the fastest athlete over 10 miles in history
Benard Kibet Koech, who holds the world 10-mile best, has been provisionally suspended by the Athletics Integrity Unit for the use of a prohibited substance.
The case revolves around his athlete biological passport, which is used by the anti-doping authorities to both deter and detect adverse findings.
The Kenyan ran a superlative 44:04 for 10 miles in Japan two years ago, taking apart Haile Gebrselassie’s previous world best of 44:24 from 2005.
Koech backed that time up by finishing fifth in the 10,000m at the 2023 World Athletics Championships, before placing eighth in the half-marathon at the inaugural World Road Running Championships in Riga.
His personal best of 58:45 over 13.1 miles came at the 2023 Ras Al Khaimah Half Marathon, a race in which Koech beat compatriot Daniel Kibet Mateiko by just four seconds.
Last summer, Koech recorded 26:43.98 for fifth over 25 laps at the Paris Olympics, finishing only behind Joshua Cheptegei, Berihu Aregawi, Grant Fisher and Mohammed Ahmed. He is yet to compete this season.
Koech is the fourth Kenyan to be provisionally suspended by the AIU this year after Ronald Kimeli Kurgat, Kibiwott Kandie and Sheila Chelangat.
