how to detect a user who changed a particular file in Linux.

Hi all, (Note : I'm writing this mail to this kernel group as I did not find any suitable mechanism in application level for my below need). If a file modified by some user then how can we detect that user who modified it. Linux audit was not suitable for my need. Can this be achieved through kernel driver/module. Any other suggestions/help would be welcome. Thanks in advance. Regards, Ravikumar.