April Lampros says she was a student at the Fashion Institute of Technology, and she says he offered to mentor her in the fashion industry. After showering her with gifts and flowers, April claims they met up in 1995 at a SoHo bar, where he plied her with alcohol ... and then brought her back to his room at the Millennium Hotel.

In the docs, April says she started to feel ill and as if "the walls were closing in on her" as Diddy allegedly started to force himself on her. She says she was still conscious, but unable to defend herself when he began raping her. April says she woke up the next morning "nude, sore and confused."

April says months later, she heard from Diddy, as he began pursuing her again. She claims he lured her with access to music industry events. In the lawsuit, her attorney describes her as a "hopeful yet naive college student and took Mr. Combs at his word and believed that the first rape was a possible mulligan and decided to give him a second chance."

She claims they were on their way to dinner, walking to his car in a parking garage ... when he forced her to perform oral sex on him. April says a garage attendant saw them, but Diddy was unfazed.

After that alleged incident, April says she rejected his continued invitations, and he grew angry  ... calling her incessantly and threatening to blacklist her in the industry. She claims he developed a "mobster persona."

April claims there was an incident in 1996, when he "ordered" her to his apartment, and when she got there, she was introduced to Kim Porter. She claims he forced ecstasy down her throat, and then demanded she have sex with Kim while he masturbated. Eventually, she alleges he raped her again.

April says she finally broke things off in 1998, but then had a run-in with Kim at a restaurant where April was working. According to the suit, Kim told the restaurant owner April had tried to poison her, and if he didn't fire her, Diddy would shut down his business. April says she was fired.

In the docs, filed by Tyrone Blackburn, April says she and Diddy ran into each other once more, in Rockefeller Center around the end of 2000 or early 2001, when, she points out, he was dating Jennifer Lopez. After exchanging pleasantries, she claims Diddy ended up coming back to her apartment ... where he suddenly "violently grabbed her and forced himself onto her" -- but she was able to fight him off, and he left.

And there's this ... sometime last year, April claims someone told her then-boyfriend he had seen a video of her having sex with Diddy. In the suit, she says she's been told Diddy recorded the sexual encounter without her knowledge, and has shown the video to multiple people.

She is suing Diddy for sexual assault, battery and intentional infliction of emotional distress -- but she also lists Bad Boy Records, Arista and Sony Music Entertainment as defendants ... claiming they enabled him to commit the crimes.

We've reached out to Diddy's camp for comment. Nothing back yet.

April's attorney is also representing Rodney Jones and Liza Gardner in the lawsuits they filed against Diddy late last year. Additionally, he's representing Grace O'Marcaigh who sued Diddy's son, Christian Combs, alleging sexual assault.