A Canadian doctor who has treated Tiger Woods and other elite athletes has been charged with supplying illegal drugs.
Dr Anthony Galea is accused of giving unlawful drugs, including human growth hormone (HGH), to at least three US professional football players.
The Toronto-based physician has denied any wrongdoing.
Woods said recently he had been treated by Galea, but categorically denied using performance-enhancing drugs.
In a federal criminal complaint filed in Buffalo, New York, Dr Galea was charged with unlawful HGH distribution, lying to US officials, conspiracy to defraud, smuggling and interstate commerce with the unapproved drug actovegin.
Actovegin, a drug extracted from calf's blood, is illegal in the US and not approved for use in Canada.
According to court documents, Dr Galea's clients include at least three current or former National Football League (NFL) players, one of whom allegedly had two HGH kits delivered to his home, while another received actovegin injections.
Charges involved only unnamed NFL players, although Dr Galea is also known to have treated other sports figures, including world golf number one Tiger Woods and several prominent baseball players.
Woods said the only treatments he received in five meetings with Dr Galea were for blood spinning, where a person's own blood is placed in a centrifuge to separate the platelets from the red blood cells.
The platelets would then be injected into the injured area on the athlete.