PITTSBURGH — A cyclist who was a U.S. Anti-Doping Agency witness against Floyd Landis in 2007 has pleaded guilty to conspiracy to distribute human growth hormone and another performance-enhancing drug.

In a Pittsburgh federal court on Wednesday, Joe Papp admitted to conspiring with a Chinese manufacturer to sell drugs over the Internet to more than 180 customers including cyclists and other athletes.

Authorities have not identified any of Papp's customers and the terms of the plea agreement are under seal.

In the Landis case, Joe Papp acknowledged his long pattern of drug use and testified about the ways synthetic testosterone helped him recover after races. Landis won the 2006 Tour de France but was later stripped of his title.

Papp received a two-year ban for doping based on his acknowledgments.