Former world record holder and Olympic gold medallist Roland Schoeman has been given a one-year ban after testing positive for a prohibited substance.
The 39-year-old South African won 4x100m relay gold at Athens 2004.
He tested positive in May last year for GW501516, classed as a hormone and metabolic modulator.
The ban is backdated and ends on 17 May, meaning he would be eligible for the Tokyo Olympic swimming event starting on 25 July.