Updated 2:23 p.m.:
Michigan Department of Corrections public information officer John Cordell reacted to the report by saying, "This is why we do audits. It looks like we came up short. We'll be sure to correct our procedures in the future."
Auditors say officials at Newberry Correctional Facility in the upper peninsula haven't been listening in enough on their prisoners.
The Associated Press reports:
The prison is supposed to document that it monitors at least 50 phone calls a month by inmates. State auditors say they fell short of that target by half during a three-month period earlier this year.
The auditors said phone monitoring is an important part of keeping prisoners from violating prison policies or state law.
The medium security prison in Newberry can hold 1,072 people.
The Michigan Department of Corrections holds more than 43,960 prisoners in 34 correctional facilities around the state.