Image copyright AP Image caption CJ Spillman is the latest NFL player to be involved in an assault investigation

American football player CJ Spillman is being investigated over an alleged sexual assault, police say.

The 28-year-old, who plays for NFL side Dallas Cowboys, has not been arrested or charged.

The attack allegedly took place at a Texas hotel in the early hours of 20 September, according to Grapevine police spokesman, Sgt Robert Eberling.

The case adds to a recent spate of high-profile incidents involving American football players.

Earlier this month Baltimore Ravens running back Ray Rice was suspended indefinitely after a video emerged of him punching his then-fiancee.

After Rice was suspended, Minnesota Vikings star running back Adrian Peterson was indicted on child-abuse charges.

Image copyright Reuters Image caption Roger Goodell's handling of the Ray Rice abuse case has brought him criticism from NFL fans

Image copyright Reuters Image caption Video emerged showing Rice punching his then-fiancee

And Arizona Cardinals running back Jonathan Dwyer has been charged over accusations he broke his wife's nose during a domestic dispute in July.

The latest incident allegedly took place at the Gaylord Texan Resort and Convention Center, where the Dallas Cowboys stay.

Spillman, a defensive back, played against the St Louis Rams the next day.

Sgt Eberling said no other details were being released because the investigation was ongoing.

There has been no immediate response from the Cowboys. Spillman's agent and lawyer declined to comment, the Associated Press said.

On Tuesday, Cowboys coach Jason Garrett told staff that the club would not allow players accused of domestic violence to play.

Critics have been calling on NFL Commissioner Roger Goodell to step down after Ray Rice initially received just a two-game ban for his assault.

In a public statement earlier this month, Mr Goodell said he "got it wrong" in his handling of the Rice case and pledged to implement new personal conduct policies.

The league has announced it is hiring four women as advisers on domestic violence.