Olympic 100m hurdles champion Brianna McNeal says she is “clean” despite her provisional suspension from athletics for breaking anti-doping rules.
McNeal, 29, won gold at the 2016 Rio Olympics and was world champion three years earlier.
The Athletics Integrity Unit has accused the American of “tampering within the results management process”.
“The system is pretty messed up if you ask me but that’s another topic for another day,” she said.
In an Instagram post McNeal added it had been “tough few weeks” after injuring an ankle and also catching Covid-19.
She added: “As far as my situation goes, I am still me! Very clean, very honest and transparent.
“Once all of this blows over I will provide more details of what’s actually going on.”
McNeal missed the 2017 World Championships while serving a one-year ban for missing three drug tests.
Tampering or attempted tampering with any part of doping control carries a ban of up to four years if proved.
As McNeal has served a ban in the past, if found guilty she could face a ban of up to eight years.