The schema is SYSPROC.
EXECUTE privilege on the ADMIN_REMOVE_MSGS procedure. The fenced user ID must be able to delete files under the directory indicated by registry variable DB2_UTIL_MSGPATH. If the registry variable is not set, then the fenced user ID must be able to delete the files in the tmp subdirectory of the instance directory.
In a non-restrictive database, EXECUTE privilege is granted to PUBLIC when the procedure is automatically created.
CALL SYSPROC.ADMIN_REMOVE_MSGS('24523_THERESAX')
The CALL statement that invokes this procedure with the appropriate operation_id can be found in the MSG_REMOVAL column of the first result set returned by ADMIN_CMD procedure.