Hi,
I don't know why organizations follow the procedure of reference checks after giving the offer letter. Imagine all the wastage of time and money when, after finishing all the procedures, you find out that the candidate is fake. I have seen different trends among companies - some conduct reference checks before the HR round, some do it after deciding on the candidates to be shortlisted, i.e., before issuing the offer letter, and some conduct it at a later stage.
However, prevention is better than cure. The procedure I follow in my company is that although employees provide their reference numbers, I rarely use them. Instead, I try to obtain the contact details of the candidate's previous company on my own. I randomly call to inquire about the candidate because the phone number they provide is likely prearranged. Therefore, to avoid any potential biases, I use numbers obtained from the company website or directory. This method ensures a foolproof check. Previously, in our company, we had outsourced this task to agencies that conducted thorough background and professional checks.
So, it's your call now!