who can do a dbimport

Hi, I'm the UNIX admin and rather new to Informix. I've been told that do to a dbimport, one must be logged in using the 'informix' login. As a UNIX admin, I really question if this is neccessary. I've made a group 'informix' and the user informix is in that group as are some users who wanted the 'dbimport' capability. The users 'dbimport' attempts failed and they think the reason is that they did not do this as informix. Can someone help with what users can really do a 'dbimport'? Chuck