YORK, Neb. (AP) — The York County Sheriff’s Department has denied allegations that local jail staffers have been eavesdropping on phone conversations between inmates and their attorneys.

In a warning letter sent Thursday to police, American Civil Liberties Union of Nebraska’s legal director Amy Miller says her office has received complaints from attorneys and detainees who are concerned that the department is monitoring their phone conversations. Miller requested that the department review procedures to ensure the staff understands those calls and visits are confidential.

York County Sheriff Dale Radcliff denies that his department has ever listened to exchanges between inmates and attorneys.

The sheriff has turned the letter over to the county attorney’s office.