Brendan Paul, Diddy’s alleged “drug mule” — who’s been given immunity by Judge Arun Subramanian to testify in the music mogul’s federal trial after confirming to the judge he’s received a subpoena and intends to invoke the 5th Amendment — took the stand in the federal trial Friday … and the testimony is expected to revolve around drugs, TMZ has learned.
The charges against Paul were dropped after he completed a pretrial diversion program … and, now he’s testifying at his former boss’ trial.
Sources with direct knowledge told us all about Paul … who served as Diddy’s personal assistant for 18 months.

He’s a former Syracuse University basketball player who wanted to break into the music business … and, when he met music executive Elie Maroun — once Diddy’s manager — he was linked up with Puffy. Diddy interviewed Paul and hired him.
Our sources say Brendan’s testimony will mirror testimony we’ve already heard from other assistants … ’cause Paul did similar jobs — allegedly obtaining some drugs for the music mogul.

However, whether he was a “drug mule” will be a contested topic … and, we’ll have to wait and see what the prosecution and defense say.