The United States Anti-Doping Agency has warned a 90-year-old cyclist ©USADA

A 90-year-old cyclist has accepted a public warning for an anti-doping violation.

The United States Anti-Doping Agency (USADA) announced the sanction against Carl Grove who tested positive for epitrenbolone, a metabolite of the banned steroid trenbolone.

He failed on July 11 after setting an age-group world record at the Masters Track National Championships.

USADA said that, following an investigation, contaminated meat Grove had eaten on July 10 was "more likely than not" to have been the cause of the failure.

Before eating the meat, Grove had tested negative for banned substances after an in-competition test on July 10.

During the investigation, it was also determined that a supplement Grove used before July 11 was contaminated with clomiphene.

The cyclist provided USADA with information about supplements he used, but none listed clomiphene or other banned substances on their labels.

Detailed analysis subsequently conducted on the supplement by the World Anti-Doping Agency-accredited laboratory in Salt Lake City confirmed the presence of clomiphene in one of the supplements, however.

Grove, from Bristol, Indiana, has now been disqualified from his July 11 race.

"USADA announced today that Carl Grove, an athlete in the sport of cycling, has accepted a public warning for his anti-doping rule violations," a USADA statement said.