A confidential 2003 manual for operating the Guantánamo detention center shows that military officials had a policy of denying detainees access to independent monitors from the International Committee of the Red Cross.

The manual said one goal was to “exploit the disorientation and disorganization felt by a newly arrived detainee,” by denying access to the Koran and by preventing visits with Red Cross representatives, who have a long history of monitoring the conditions under which prisoners in international conflicts are held. The document said that even after their initial weeks at Guantánamo, some detainees would not be permitted to see representatives of the International Red Cross, known as the I.C.R.C.

It was permissible, the document said, for some long-term detainees to have “No access. No contact of any kind with the I.C.R.C.”

Some legal experts and advocates for detainees said yesterday that the policy might have violated international law, which provides for such monitoring to assure humanitarian treatment and to limit the ability of governments to hold detainees secretly.