@SuperHero
The existence of genuine Whatsapp, photo or video evidences is impossible because the lady is 100% chaste. There is no man in her life except her husband nor has ever been. Of course, evidence can be "manufactured" nowadays with the advent of Photoshop and other new softwares. However, husband hasn't produced any evidence yet.
But the wife is afraid that the husband can easily produce false witnesses if not false evidence. The husband has a very good circle of friends (male friends), some of them since childhood. They will be ready to help him for anything. The wife is afraid some of those friends might show up in court, concoct false stories against the wife's character and malign her sobriety.
@All
I am still awaiting answer to my original queries:
1) How to prove conclusively that the lady is chaste and there is no man in her life?
2) How to prove she is a strict teetotaller? Any medical test existing in India for it?