Nobody really addressed a fix.
But if the admins are out of touch and you have full access to the control panel.
First option is to remove that member as a moderator. (This may cause ill will to the member)
Also not knowing the work around that allows this leak.
Check to see if the member is in a special group that allows admin access in the control panel.
CP>> member management
Search for user and view what groups he is in.
He may inadvertently be added to the administrator group that would allow him to become a member. To view private topics.
If he is just in a moderator group and that group has cp access then you have a issue where it will impact all moderators.
If it were me I would ban him from the site due to abuse of access rights.
There is no legit reason to view another members private messages, Unless requested to do so by the member if they are having a issue with the feature.
Last edited by Ruben; 04/30/2010 4:40 PM. Reason: Added Comment
