Diddy Accuser Says She Purchased Cocaine, Other Drugs for Him and Cassie

Bryana Bongolan -- a fashion designer who is suing Diddy for $10 million -- took the stand against him ... and, she testified that she bought drugs for him and Cassie.

Bongolan -- who also goes by the name "Bana" -- began her testimony Wednesday morning in the rap mogul's federal trial in NYC, and she touched on the allegations introduced in her civil suit ... once again alleging Diddy held her over the edge of a balcony and threw a knife at Cassie during a different incident.

In the lawsuit, Bryana said he came over to Cassie's apartment and attempted to grope her, and she says when she resisted, he allegedly took her out to the balcony and held her off of it

Bongolan said Wednesday she was sleeping on the couch with her ex-girlfriend when Diddy stopped by. She said she brought her ex to a bathroom to shield her from what she anticipated was going to happen next.

She said she went out to the balcony -- she said she either lit up or was about to light up a blunt -- when Diddy came up behind her and lifted her onto the railing of the balcony. She said Diddy yelled, "You know what the f*** you did!" But she responded she didn't, prompting Diddy to toss her against the balcony furniture.

Bongolan said Cassie stepped onto the balcony and asked Diddy, "Did you just hang her over the balcony?" Bongolan said Diddy then left, and she left too, with a "huge bruise on my leg and back and neck pain." Diddy denies Bongolan’s allegations against him.

Prosecutors also asked Bongolan about her friendship with Cassie, and she testified they often took drugs and went shopping together. Bongalon says Diddy gave her and Cassie numerous drugs over the years ... including ketamine, cocaine, marijuana and a drug she referred to as "G."

Bongolan testified she didn't just use drugs with Cassie either ... she also purchased them for her -- supplying her with a steady stream of OxyContin. She says Cassie always paid her back for the drugs. As for Diddy, Bongolan says she bought cocaine for him on one occasion.

BB says she had one experience with Puff that particularly frightened her ... claiming that on a shopping trip with Cassie in April 2016 -- one month after Diddy beat up Cassie at the InterContinental Hotel -- Diddy texted Cassie asking where they went.