Law enforcement sources are clapping back Thursday at prosecutors' allegations that lead detective Nicholas DiGaudio instructed one of Weinstein's alleged victims to delete relevant information from her phone prior to turning it over to prosecutors.

Sources familiar with the case say DiGaudio is calling BS ... claiming he only told the alleged victim she could do whatever she wanted with "intimate stuff" from her phone before turning it over to investigators, including potentially embarrassing photos.

As for the prosecutors' assertion that DiGaudio also told the alleged victim "we just won't tell [the assistant D.A.]" about the deleted photos, sources say he has "no recollection" of ever making that statement.

This is another huge setback for prosecutors. They already agreed to dismiss a sexual assault case where the alleged victim claimed she was forced to engage in oral sex with Weinstein ... this after a witness came forward and said she told Detective DiGaudio the alleged victim told her the sex was consensual. DiGaudio allegedly told the woman not to cooperate.

Prosecutors say they will still go forward with the remaining charges, but whenever the D.A. and the cops are at odds, the case is on life support at best.