One of the most stunning Diddy allegations yet comes from an accuser who claims he was just 10 years old when the Bad Boy mogul forced him to perform a sex act to get his shot at stardom.

The new lawsuit was filed Monday in NY state by a John Doe accuser, and according to the suit, he flew to NYC with his parents in the summer of 2005 for an audition with Diddy. He claims Diddy said he wanted to meet him alone, before meeting his whole family.

In the docs, obtained by TMZ, the plaintiff says he met Diddy at a hotel near Madison Square Garden, and he says he rapped several songs, which went well — Diddy allegedly said he could make the kid a star.

According to the suit, Diddy asked how badly he wanted to be a star, to which he replied, he would “do anything.” At that point, he alleges someone from Diddy’s team gave him a soda, and after drinking it he started feeling a “little funny.” He believes it was laced with GHB or ecstasy.

The alleged victim says Diddy then told him to come closer, and said something to the effect of “You have to do some stuff you don’t want to do sometimes.” Then Diddy allegedly took out his penis and forced him to perform oral sex — and, according to the suit filed by attorney Tony Buzbee, the plaintiff then passed out.

When he woke up, he alleges his pants were undone, and he believed he’d been raped.

The plaintiff claims he was lethargic, still feeling the effects of the drugs, and when he cried for his mom and dad — Diddy alleged threatened to harm the kid’s parents if he told them what had happened.

He claims he did tell his parents, anyway, but they were all terrified to report it to police due to the potential consequences.

Since then, the plaintiff claims he’s lived with night terrors, and was deprived of having a normal childhood. He’s suing Diddy and all of his companies for gender-motivated violence, and he’s seeking damages.

Diddy’s legal team tells TMZ … “The lawyer behind this lawsuit is interested in media attention rather than the truth, as is obvious from his constant press appearances and 1-800 number. As we’ve said before, Mr. Combs cannot respond to every new publicity stunt, even in response to claims that are facially ridiculous or demonstrably false.”

They add that they’re fully confident in the judicial process and believe, “The truth will prevail: That Mr. Combs never sexually assaulted or trafficked anyone — man or woman, adult or minor.”