The Balco steroid distribution case took a new turn with the indictment of chemist Patrick Arnold for his alleged part in the scandal on Thursday. Arnold is charged with being a "prohormone manufacturer", meaning he is suspected of designing and producing the performance-enhancing drugs.
"We've taken another step in the effort to end the use of performance-enhancing drugs," said US attorney Kevin Ryan.
Balco founder Victor Conte was given a four-month prison sentence last month.