Hi Feroz,
I understand your motives. And your problem.
To answer your question: YES, it can be done.
Of course in the process of deleting these records a malicious user will leave *some* traces.
With enough skill however, these traces can't be linked to the deleted data by people without *deep* technical understanding.
In other words: you can delete this data without leaving traces in the "usual places".
I can give you some ideas how to detect such activity.
However, I can't discuss these without giving hints how to manipulate data in the first place.
And clearly, I don't want to give a recipie for fraud on SCN.
If you want to get more details, pls contact me via Twitter.
(No, I will not disclose this information on Twitter, either. Takes more than 140 characters anyway...)