Dear Gajinder Singh,
Background Verification (BGV) Process
Background Verification (BGV) is an important activity in the recruitment process. To conduct the BGV, with whom did you correspond? Was it with the HR department of the employee's previous company? We do not know the culture of that company. However, if the HR is non-communicative, you may send the BGV form by post. Address it to the MD of the company. Write a letter to them stating that they need not send the reply by post but just mark the answers and send the scanned copy.
If communication with the MD also remains unanswered, then you need to decide whether to proceed with the BGV or not. However, for a waiver of the BGV, obtain permission from the competent authority in your company.
Alternative Measures
If the employee's past company is uncooperative, you may obtain a declaration from the employee. For the contents of the declaration, you may click here. This is a reply to another post, but some parts of the contents are useful.
Thanks,
Dinesh Divekar