2:30 PM PT -- Diddy's attorney Erica Wolff tells TMZ ... "Mr. Combs is shocked and disappointed by this lawsuit. In an attempt to rewrite history, Dawn Richard has now manufactured a series of false claims all in the hopes of trying to get a pay day -- conveniently timed to coincide with her album release and press tour."

She adds, "If Ms. Richard had such a negative experience with Making the Band and Danity Kane, she would not have chosen to continue working directly with Mr. Combs for Dirty Money, nor would she have returned for the Making the Band reboot in 2020 or agreed to be featured on 'The Love Album' last year. It’s unfortunate that Ms. Richard has cast their 20-year friendship aside to try and get money from him, but Mr. Combs is confidently standing on truth and looks forward to proving that in court."

Diddy is facing yet another lawsuit from a new accuser, a former bandmate who claims the music mogul belittled, terrorized and sexually abused her while she also witnessed him savagely beat his ex, Cassie.

According to the suit, obtained by TMZ ... Dawn Richard says she got caught in Diddy's web as a participant on his 2004 MTV show "Making The Band," with the Bad Boy CEO manipulating her by promising to advance her singing career if she relented to his alleged twisted demands.

The former Danity Kane member said during on-set auditions, Diddy called female contestants "fat," "ugly," "bitches" and "hoes." She said Diddy had particular disdain for her because she was young and excited to work with such a famous person.

In 2005, the court docs say, Richard saw another of Diddy's former girlfriends, Kim Porter, crying as she left a music studio with her face all banged up. It was then Richard says she realized Diddy was capable of violence and her life could be in danger.

A year later, Richard was present when Diddy was first introduced to Cassie, invading her space while transfixed on her in a predatory fashion, according to the docs. In 2009, she says she personally witnessed Diddy -- high on drugs -- throw Cassie against a wall, choke her and drag her up a flight of stairs in his L.A. home.

Richard says Diddy also hurled a scalding pan of eggs at Cassie while yelling, "I’ve been asking you for my s**t; I can’t stand you bitch, you never do it right!"

On other occasions, Richard says Diddy socked Cassie in the face and wrapped his hands around her throat, attempting to strangle her inside his L.A. mansion.

At some point, Richard says she and others -- including her Diddy-Dirty Money bandmate Kalenna Harper -- showed their support to Cassie and advised her to leave Diddy, who found out about the conversation and threatened ...  "Y’all bitches don’t get in my relationship," adding, "Don’t tell my bitch [Cassie] what she need to be doing ... Just make money and shut the f**k up ... I end artists ... I shelve careers ... You could be missing ... You bitches want to die today."

Meanwhile, Richard says she, too, became a victim of Diddy's abuse, forcing her to rehearse 48 hours at a time without sleep. As a result, she says she dropped a lot of weight and became dehydrated and fatigued while suffering awful rashes.

She says one time Diddy demanded she come to his Miami home, where he was only wearing underwear. When she asked him to put on clothes, Diddy refused, screaming, "This is my f**king house!"

Diddy's treatment of Richard got worse she says between 2009 and 2011. Richard says Diddy once barged into her dressing room while she was naked at his recording studio. She says Diddy inappropriately touched her breasts and butt.

Diddy, she says, also locked her in a car with heavily tinted windows for two hours as she screamed for help, even calling her dad for help.

Richard claims her dad traveled from Baltimore to New York to free his daughter and confront Diddy, threatening to report him to the police. But, she says, Diddy told her dad, "Think about your daughter" and "think about your daughter's career."

We've reached out to Diddy's reps ... so far no word back.