American Olympic team boxer Virginia Fuchs has been cleared of a doping violation after the United States Anti-Doping Agency (USADA) determined that banned substances in her sample had been transmitted during sex with her boyfriend.
The 32-year-old flyweight had tested positive for two substances banned by the World Anti-Doping Agency (WADA) in an out-of-competition urine test on February 13, the USADA said in a statement.
"The low amounts of letrozole metabolite and GW1516 metabolites detected in her sample were consistent with recent exposure to the substances via sexual transmission," the USADA said it had determined in its investigation.
The anti-doping body said Fuchs's partner had been using therapeutic doses of the two substances and that Fuchs bore no fault or negligence for the adverse finding and would therefore not be banned.
"We strongly believe this case and others like it, including meat contamination and prescription medication contamination cases should be considered no violation," USADA chief Travis Tygart said.
Fuchs narrowly missed out on qualifying for the Rio Olympics in 2016 and has now set her sights on next year's delayed Tokyo Games.
"This has been a huge lesson for me and now that is over, I'm fully focused on preparing for Tokyo," she wrote on Twitter.
The usual punishment for the use of banned substances is a four-year ban from all WADA-compliant sports.
In 2017, USADA allowed middle-distance runner Ajee Wilson off without a suspension, concluding that traces of an anabolic agent in her sample had come from contaminated beef.