R. Kelly's Attacker Moved to New Prison, Feds Say Threat's Gone

R. Kelly's renewed plea to get sprung from jail is getting push back from Uncle Sam, who says his most recent concern -- getting attacked behind bars -- has been neutralized.

Federal prosecutors just filed a reply to R. Kelly's latest request to be released on bail after he was ambushed and beaten by a fellow Chicago MCC inmate ... a guy Kelly says could've cost him his life. The government's response? Relax, it was a one-and-done.

According to the docs, obtained by TMZ, the feds say the attack on R. Kelly was a one-time, isolated event -- and that it can't happen again, at least not with the same guy ... because he's been moved to a new facility in Michigan.

So, in their eyes, the threat has left the building.

The feds also dispute R. Kelly's claim the attacker allegedly told a doctor on site that he needed to attack the singer for attention on his own case -- claiming the doctor denied that convo ever happened. That said, they also point out that if R. Kelly's still sour about his injuries ... he can take it up in civil court.