HUNTSVILLE, Texas (AP) — A warden has been demoted and transferred from a Texas prison where a supervisor resigned and four corrections officers were fired amid allegations they orchestrated the planting of two screwdrivers in an inmate's cell.

Texas Department of Criminal Justice officials have said the planted contraband at the Ramsey Unit south of Houston appears to be isolated and unrelated to a quota system involving a supervisor ordering officers there to write disciplinary reports. The agency's Inspector General Office has been investigating.

Prisons spokesman Jeremy Desel says there's no evidence of further quota activity at the system's 104 units. He also says staffers serving as counsel for inmates accused in disciplinary cases no longer report to wardens but to the agency's Division of Administrative Review and Risk Management to increase their independence.