A lawyer representing Bosch did not respond to messages seeking comment.

As the sports world braces for the expected flurry of suspensions, which have been the subject of speculation for months, the story of Tony Bosch, the quasi doctor, and Porter Fischer, his client turned investor turned whistle-blower, reveals an underbelly of shady business practices and dubious drug deals that extend from a Coral Gables office park to Yankee Stadium.

It features a cast of superstar athletes who drive Maybachs and help sell out ballparks; high-priced baseball investigators, including F.B.I. agents and a former Secret Service official; and Florida personalities who could be extras in a Carl Hiaasen novel.

Bosch, 49, with his black hair greased back and dress shirts untucked, was a familiar figure on the Miami scene. People who know him said he could often be spotted at the hottest restaurants or at the bar at the Ritz-Carlton Key Biscayne. His ground-floor clinic sat near the University of Miami and its baseball stadium, Alex Rodriguez Park.

Fischer, 49, was a regular at the Boca Tanning Club in Coral Gables who had cycled through a series of marketing jobs. He had struggled with his cholesterol and wanted to lose weight, so he sought the advice of Bosch, who for $375 a month prescribed him a cocktail of HCG, a hormone, along with testosterone and vitamin B12. He later added Anavar, a steroid, which Bosch called “the stuff Lance Armstrong takes,” Fischer said.

Bosch had also begun working with some of the biggest names in baseball, earning their trust and supplying them with banned substances like human growth hormone, according to baseball officials. In 2009, baseball investigators found evidence that the 12-time All-Star Manny Ramirez had received a banned drug from Bosch’s facility.

Fischer said he and Bosch quickly connected — they had attended the same high school, graduating a year apart. At first, Fischer was impressed with Bosch, and said that with his treatments, “the weight started falling off.”