Keneth Kiprop Renju, winner of the Prague half-marathon in April, received a five-year ban Friday as the latest in a long list of Kenyan athletes suspended for suspected doping.

The 26-year-old has been banned for the “presence/use of a prohibited substance (Methasterone)”, the Athletics Integrity Unit said on Twitter.

Renju’s ban is backdated to May 13 and all his results since March 20 have been annulled. He also won the Lisbon half-marathon on May 8.

Kenya’s athletics reputation is again taking a pummelling after the suspension this year of an unusually large number of long distance runners.

Among the top names suspended are 2021 Boston marathon champion Diana Kipyokei and marathon and mountain racer Mark Kangogo. Over 20 Kenyan athletes have been hit with sanctions this year alone.

The problem is not new — the athletics powerhouse has been in the top category of the World Anti-Doping Association’s (WADA) compliance watch list since February 2016.