Profoundly disabled young men were forced into "fight club" style battles by the people hired to care for them in a Texas residential facility, US police say.

The staged battles - which appear to have been going on for at least two years - were discovered when police reviewed the video on a mobile phone camera found lying in the road.

"It's some of the worst child abuse I've seen in over 30 years," Corpus Christi Police Captain Tim Wilson said.

"Sometimes we see isolated incidents. What's appalling about this is that it appears to be organised."

The video footage showed staff members provoking the young men until they became physically violent, then shoving them at each other to make sure they fought.