Prosecutors going after Kim Zolciak's son Kroy Biermann Jr. for an alleged sexual battery just filed emergency docs in his criminal case ... and it looks like they want to talk to some underage kids.

According to the court docket, obtained by TMZ, the prosecutors filed a motion asking the court to order forensic interviews of "minor children." No other details are available at this time.

Forensic interviews are conducted by professionals, and it appears the information gathered would be used in the case.

As TMZ first reported, Kroy Jr. is facing several felony charges for sex crimes. The 15-year-old is accused of sexually assaulting a schoolmate in a local gym.

At a recent hearing, prosecutors claimed Kroy was already on probation for a previously unknown case ... and authorities say they found videos on his phone showing him having sex with an underage relative.

The court recently set his bond at $200K.