With respect to the details of that company, please speak to them and document the conversation with date, time & person's name. The employee who is joining your organization, should submit the offer letter, resignation acceptance letter/experience letter along with salary statement and most important FORM 16 (if the company has provided him) if not; then do note this ...along with an underwriting to the HR. These cases are to be internally closed by the HR Person assigned/authorized for the same. Please file the same along with the Back ground report which you have received from vendor and file it in personal file for future documents. here the person gets benefit of doubt as it is not his mistake that the company no longer holded records.