Updated

Oklahoma prison officials say officers discovered a false wall with an "escape hatch" inside a halfway house that holds prisoners who are nearing the end of their sentences.

The Oklahoma Department of Corrections said Friday that officers found the false wall while searching for contraband at the Center Point halfway house in Oklahoma City. Officials say inmates removed drywall to create a pathway outdoors then concealed it with a false wall. The department says inmates would check in with security then sneak out through the hatch.

Corrections Director Joe Allbaugh says the department will investigate security measures at the halfway house and says some inmates may see their sentences lengthened because of the escapes.

Officials also seized 18 cellphones, 87 phone chargers, 39 syringes, marijuana and methamphetamine.