Diddy Receives More Support From 'Victim 3' Ahead of Mogul's Sentencing

Diddy is getting even more support from the woman who was supposed to testify against him at his federal criminal trial ... ahead of his sentencing tomorrow for his Mann Act convictions.

Virginia Huynh -- better known as "Gina" during Diddy's trial -- wrote a letter to the judge on behalf of Diddy, blasting prosecutors for pressuring her into becoming "Victim 3" in the indictment. As you know, Diddy was found guilty in July on 2 counts of the Mann Act -- illegally transporting individuals across state lines for the purpose of prostitution.

In her letter, Gina says she fully cooperated with prosecutors, sitting down with them 3 times and answering all their questions. She says she turned over every stitch of evidence ... notably photos, videos and text messages.

Gina says she felt pressured by prosecutors to play the role of a victim -- even when she told them she was not a Diddy victim.

But, Gina says, the prosecutors kept insisting she was, saying she had been sex-trafficked and forced into prostitution by the music mogul.

Yet, in the letter, Gina stands firm in her belief she was never trafficked, nor did she ever engage in prostitution with Diddy or anyone else. And Gina says she would have testified to tell her truth if she had been called to the witness stand.

You may recall, Gina was going to testify for the prosecution, but prosecutors told the court before the trial started they had lost touch with Gina and her attorney. She later penned a letter under her real name asking the judge to release Diddy on bail.