Paul, a former Syracuse men's basketball player who worked as Diddy's main assistant, was arrested in March at the Miami-Opa Locka Executive Airport after feds searched his bag and allegedly found cocaine and marijuana candy. He was arrested and taken into custody, at the same time the feds were raiding Diddy's Miami and L.A. mansions.

The 25-year-old, who was extremely close to Diddy and was privy to Diddy's comings and goings, pled not guilty. His lawyer, Brian Bieber, tells TMZ, "We will be dealing with this case in the courtroom, not the court of public opinion."

As we have extensively reported, Diddy is in the crosshairs of the feds. He's being investigated for sex trafficking, illegal gun possession and other alleged crimes.

The wild card now is Brendan Paul. The feds are clearly not eyeing this as a major crime, but they're now in a position to offer Paul a deal ... possibly dropping or reducing the charges in return for cooperation in the Diddy case.

Stay tuned ...