United States NFL player CJ Spillman is being investigated over an alleged sexual assault, police said yesterday.

Spillman has not yet been arrested or charged, with the attack allegedly taking place at a Texas hotel in the early hours of 20 September.

The 28-year-old, currently playing for Dallas Cowboys, played against the St Louis Rams the following day.

Grapevine police spokesman Sgt Robert Eberling said no other details were being released due to the fact that the investigation was ongoing.

Spillman’s agent and lawyer, as well as the Cowboys, are yet to comment but on Tuesday, head coach Jason Garrett told staff that the club would not allow players accused of domestic violence to play.

He said: “Part of what our jobs are as coaches is to create the right environment for our players to function both on and off the field.

“So we need to be clear about where we are and we need to be clear that we have a structure in place to help anybody who has any off-the-field issue. 

“We have a lot of resources here to help guys, if you’re dealing with anything off the field. That was the first message. Having said that, there are standards we have about all off-the-field behaviour and certainly domestic violence applies to that. We’re very clear about how we’re going to handle things.”