Outside The Lines catches up with Biogenesis founder Tony Bosch, who discusses the PED allegations against him. (5:03)

Major League Baseball officials met Friday with Dr. Daniel Carpman, an anti-aging doctor whose name appears on forged prescription forms tied to a South Florida clinic suspected as a source of performance-enhancing substances for more than 30 players -- among them Alex Rodriguez, Nelson Cruz and Ryan Braun.

Carpman told "Outside the Lines" he was deposed by MLB officials in Miami for five hours Friday, noting that part of the time was spent discussing a series of documents MLB has obtained in its investigation of Tony Bosch, the self-described biochemist who headed the now-shuttered Biogenesis of America clinic.

Bosch is the subject of a civil lawsuit filed by MLB and a Florida Department of Health investigation. He could face felony criminal charges if connected to forged medical prescriptions.

Bosch used prescription forms that contained forged signatures, stamped with the names of license numbers of legitimate physicians who apparently were unaware of the scheme, sources and documents indicate. Those drugs were prescribed to Bosch's friends and associates and delivered to professional athletes in order to avoid a paper trail, sources said.

"Outside the Lines" obtained copies of Biogenesis documents, including prescription forms bearing the signature of Carpman. When shown the forms last month, Carpman denied it was his signature -- a claim supported by a forensic handwriting expert retained by "Outside the Lines."

"It is like a robbery," Carpman said when first shown the forms. "You feel bad."

Carpman said he met Bosch several years ago at a Miami wellness clinic, where Bosch served as an adviser. Bosch does not have professional licenses, though Carpman acknowledged he "knew his stuff."

"Tony said he is an adviser," Carpman said. "But people call him doctor. And he has a lab coat. He acts like a doctor, but he is not a doctor."

Yet sources say Bosch regularly signed prescription forms, diagnosed and treated clients, provided prescriptions for clients who had not been examined by a doctor and ordered prescription drugs sent to friends and then had them delivered to some of the athletes he worked with.