Olympic long jump silver medalist Luvo Manyonga has been provisionally suspended in a doping case and could be banned from the Tokyo Games.
The Athletics Integrity Unit said it sent Manyonga a "notice of charge" in the case, which is based on suspected breaches of whereabouts rules.
The South Africanlong jumper — who had his 30th birthday on Friday — is the latest world champion to be investigated regarding whereabouts rules. The cases include missing out-of-competition doping tests or failing to update details of where they can be contacted by sample collection officials.
Manyonga won gold at the 2017 world championships in London. He finished fourth two years later in Doha.
American sprinter Christian Coleman, the 100-meter champion, is serving a two-year ban imposed after he was initially reprieved to compete at the 2019 worlds. Elijah Manangoi of Kenya, the 1,500 world champion in 2017, will also miss the Tokyo Olympics while serving a two-year ban.
Salwa Eid Naser of Bahrain, the women's 400 champion, faces a Court of Arbitration for Sport hearing in a whereabouts case. The AIU filed an appeal after an independent tribunal cleared her on a technicality.
Another United States athlete, Pan American Games triple jump champion Omar Craddock, is suspended for competition in the Olympic year while his whereabouts case is processed.
