Cassie Ventura: Star Witness For the Prosecution in Diddy Trial

Cassie Ventura dated Diddy for more than a decade ... and, now she'll likely deliver some of the most important testimony at his federal trial, starting later this month.

The singer-songwriter has played a large role in Diddy's life no doubt ... and, we're going to recap her last couple years as they pertain to Diddy's life -- beginning in late 2023 when she filed a civil lawsuit against him.

Back in November of that year, Cassie sued Diddy ... accusing him of rape, human trafficking and other crimes. It was also the first time anyone had made mention of the alleged "freak offs" prosecutors claim Diddy had -- with Cassie claiming he coordinated sexual encounters between her and male prostitutes and pleasured himself while watching.

Diddy's lawyers initially called this lawsuit a "shakedown" ... but, just a day later, he agreed to settle for an undisclosed amount.

At the time, the NYPD told us Diddy was not the subject of an investigation despite Cassie's lawsuit. Numerous other alleged victims came forward in the following months and filed similar lawsuits against the music mogul.

A few months after Cassie's lawsuits, federal agents raided Diddy's homes in L.A., New York and Miami ... and, we broke the news that Cassie was cooperating with the feds -- which, given the timing, suggests Cassie may have helped them establish probable cause for the raids.

Then, in May of last year, the now infamous tape of Diddy beating up Cassie in a hotel hallway was published by CNN. The video shows Cassie leaving a hotel room and heading for the elevators when Diddy -- wearing only in a towel -- follows her out and knocks her to the ground.

The prosecution and the defense have fired off at one another over the tape ... with Diddy's team introducing testimony by an expert witness claiming the versions of the video the prosecution aren't an accurate depiction of events for various reasons.

Four alleged victims are scheduled to testify against Diddy at his trial ... with just one of them -- Cassie -- doing so sans pseudonym.