Major federal investigations show several dozen Pentagon officials and contractors have bought and downloaded child pornography using private or government computers.

On Friday, the Pentagon released investigative reports spanning almost a decade that implicated people working with agencies and handling the United States most closely guarded secrets such as the National Security Agency, the New York Times reported.

A 2007 investigative report said that those who bought child pornography put the Department of Defense, “the military and national security at risk by compromising computer systems, military installations and security clearances.”

Some of them received prison terms of up to about five years and were ordered to pay heavy fines, according to the New York Times.

However, several suspects identified by investigators were never prosecuted, the paper added.