/usr/include/mongo/client/ is in mongodb-dev 1:2.4.9-1ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/mongo/client/authlevel.h
/usr/include/mongo/client/clientOnly-private.h
/usr/include/mongo/client/connpool.h
/usr/include/mongo/client/constants.h
/usr/include/mongo/client/dbclient.h
/usr/include/mongo/client/dbclient_rs.h
/usr/include/mongo/client/dbclientcursor.h
/usr/include/mongo/client/dbclientinterface.h
/usr/include/mongo/client/dbclientmockcursor.h
/usr/include/mongo/client/distlock.h
/usr/include/mongo/client/gridfs.h
/usr/include/mongo/client/model.h
/usr/include/mongo/client/parallel.h
/usr/include/mongo/client/redef_macros.h
/usr/include/mongo/client/sasl_client_authenticate.h
/usr/include/mongo/client/sasl_client_session.h
/usr/include/mongo/client/syncclusterconnection.h
/usr/include/mongo/client/undef_macros.h