How Can One Verify A Candidates Salary From An EX-Employer?

Hi,
Am new to the forum and this is my first post.
I work for a renowned consultancy in Pune. Can someone please tell me as to how a Company or a Background Verification Agency verifies the last drawn salary or the pay-package for a particular candidate with his Ex-employer.
Also, i've observed that companies do provide information like the employee's tenure with the company, his/her designation, behaviour, etc. but are reluctant in disclosing the pay-package for an Ex-employee.
Can someone please through some light as to how the process works. :idea:
Thanks for the support.

Dear Sidd,
Most of the org. will not disclose confidential information. Question regarding salary are very sensitive and critical to company. For salary verification why don't you ask employee to give pay slip, copy of offer letter etc.
No org. will give you these sort of information in written but if you ask them tactfully they might give you some idea.

Dear Friend,
Thanks for the reply. Nowadays most of the candidates also fake their salary slips and offer letters.
I've come across cases wherein the candidates have been genuinely working with a particular MNC but have faked their salary figures in their salary slips.
So, just wanted to know if the background verification guys have any sort of fool-proof way to tackle these kind of cases.
Thanks.

Hi!
You ask the candidate to provide the salary slip as well as his bsak Account Statement where his salary is being deposited by the ex employer
Regards
Ajay Dua