Dallas Cowboys defensive back C.J. Spillman is being accused of sexual assault.

Police say Spillman is under investigation for an incident that took place September 20th at the Cowboys' official hotel in Grapevine, Texas. The alleged attack on a woman came just a day after NFL commissioner Roger Goodell's news conference during which he promised to improve the league's personal conduct policy.

Police say Spillman has not been arrested or charged in the case.

The NFL has faced harsh criticism over the way it handled an assault case involving former Baltimore Ravens running back Ray Rice. Two more assault cases last month put NFL running backs Adrian Peterson of Minnesota and Jonathan Dwyer of Arizona on the sidelines.

Meanwhile, Carolina defensive end Greg Hardy is on paid leave while he appeals his conviction in a domestic violence case involving his ex-girlfriend in North Carolina. (Metro Networks Inc.)