NAIROBI — Kenyan sprinter Boniface Mweresa has failed a doping test and been dropped from the team for the African Championships which start in Asaba, Nigeria on Wednesday, a senior official from the Anti-Doping Agency of Kenya (ADAK) has told Reuters.

Samples from Mweresa, who won silver in the 400m and gold in the 4x400m at the 2015 African Games in Brazzaville, were taken at the June 6-8 Kenya Defence Forces Championships in Nairobi and contained a banned substance, the official said on Tuesday.

The Kenyan delegation traveled to Asaba on Monday without Mweresa, who was a member of the team at the 2013 and 2017 World Championships in Moscow and London respectively and at the 2014 and 2018 Commonwealth Games in Glasgow and the Gold Coast.

Mweresa, 24, could not immediately be reached for comment by Reuters but the athlete told local media he was innocent and had taken supplements which he had declared to ADAK.