Federal prosecutors have charged three New York prison guards with participating in the bloody beating of an inmate two years ago and falsifying documents to cover it up.

U.S. Attorney Preet Bharara alleges in an indictment that two guards and their sergeant violated the civil rights of Kevin Moore, who never physically threatened them, at Downstate Correctional Facility in Fishkill.

The indictment says a group of correction officers "brutally beat him for an extended period ... with fists, boots and batons, causing many life-threatening injuries, including five fractured ribs, a collapsed lung and facial fractures in multiple places."

Moore was being held at the Hudson Valley prison on Nov. 12, 2013 for transfer to New York City's Rikers Island.

State corrections officials didn't immediately respond to requests for comment.