KANSAS CITY, Kan. (AP) — The federal public defender's office has asked for the release of 67 inmates from a Kansas federal prison and plans to seek freedom for more than 150 others because authorities secretly recorded conversations between prisoners and their attorneys that are supposed to be private.

Most of the federal inmates are being held on drug or firearms-related cases.

The practice first came to light in a prison contraband case during which criminal defense lawyers discovered the privately run Leavenworth Detention Center was routinely recording meetings and phone conversations bet...